All 360 quiz questions in 9 units, with the correct answer and an explanation for each. Read a unit, then test yourself in the Senior 1 quiz.
1.A physical quantity is anything that:
Answer: B
Examples are length, mass and time.
2.Which of these is a fundamental (base) quantity?
Answer: A
Mass, length, time, temperature, current, amount of substance and luminous intensity are base quantities.
3.Which of these is a derived quantity?
Answer: D
Volume is derived from length × length × length.
4.The SI unit of length is the:
Answer: A
The metre (m) is the SI base unit of length.
5.The SI unit of mass is the:
Answer: C
The kilogram (kg) is the SI unit of mass.
6.The SI unit of time is the:
Answer: A
The second (s) is the SI unit of time.
7.The SI unit of temperature is the:
Answer: A
The kelvin (K) is the SI unit of temperature.
8.How many centimetres are in 2.5 m?
Answer: A
1 m = 100 cm, so 2.5 m = 250 cm.
9.Convert 3500 g to kilograms.
Answer: C
1 kg = 1000 g, so 3500 g = 3.5 kg.
10.How many seconds are in 5 minutes?
Answer: C
5 × 60 = 300 s.
11.The prefix 'milli' means:
Answer: C
1 mm = 1/1000 m.
12.The prefix 'kilo' means:
Answer: B
1 km = 1000 m.
13.Which instrument is best for measuring the length of a classroom?
Answer: A
A tape measure can measure several metres.
14.Which instrument measures the internal diameter of a pipe to 0.1 mm?
Answer: B
Vernier calipers have inside jaws for internal measurements.
15.Mass is measured using a:
Answer: D
A balance compares or measures mass; a spring balance measures weight (force).
16.The volume of a liquid is measured using a:
Answer: D
Measuring cylinders are marked in cm³ (or mL).
17.A rectangular block is 5 cm long, 4 cm wide and 2 cm high. What is its volume?
Answer: C
V = l × w × h = 5 × 4 × 2 = 40 cm³.
18.A rectangle measures 8 m by 3 m. What is its area?
Answer: C
Area = 8 × 3 = 24 m².
19.1 litre is equal to:
Answer: C
1 L = 1000 cm³ = 1 dm³.
20.A stopwatch is used to measure:
Answer: A
Stopwatches measure time in seconds.
21.To measure the thickness of one page of a book with a ruler, you should:
Answer: D
Measuring many pages reduces the error for a very small length.
22.200 sheets of paper are 2 cm thick. What is the thickness of one sheet?
Answer: B
2 ÷ 200 = 0.01 cm (0.1 mm).
23.When reading a measuring cylinder containing water, the reading is taken at the:
Answer: B
Water forms a curved surface; read the bottom of the curve at eye level.
24.Which pair is a correct quantity and its SI unit?
Answer: D
The SI unit of length is the metre.
25.Physics is the branch of science that studies:
Answer: B
Physics explains motion, forces, energy, light, electricity and more.
26.Mobile phones, solar panels and X-ray machines show that physics is closely linked to:
Answer: A
Physics discoveries lead to new technologies used every day.
27.Which of the following is a science process skill?
Answer: B
Observing, measuring, hypothesising, experimenting and concluding are process skills.
28.Which is the correct order of steps in a scientific investigation?
Answer: D
We observe, suggest an explanation, test it, then draw a conclusion.
29.Which of these is a vector quantity?
Answer: B
Force has both magnitude and direction.
30.The prefix 'micro' (μ) means:
Answer: D
1 μm = 10⁻⁶ m.
31.Mass and weight are measured in the same unit.
Answer: False
Mass is in kilograms; weight is a force measured in newtons.
32.Speed is a derived quantity.
Answer: True
It is derived from length and time.
33.1 kilometre is equal to 1000 metres.
Answer: True
Kilo means one thousand.
34.A spring balance measures mass directly.
Answer: False
A spring balance measures weight (force); a beam balance measures mass.
35.Physics is related to other sciences such as chemistry and biology.
Answer: True
For example, physics explains how X-rays and microscopes help biologists and doctors.
36.The SI unit of mass is the ______.
Answer: kilogram (kg)
One of the seven SI base units.
37.Quantities obtained by combining base quantities, such as area and speed, are called ______ quantities.
Answer: derived
For example, area = length × length.
38.The curved surface of a liquid in a measuring cylinder is called the ______.
Answer: meniscus
Read the bottom of the meniscus for water.
39.The prefix 'centi' means one ______ of a unit.
Answer: hundredth (1/100)
1 cm = 1/100 m.
40.A quantity that has magnitude only, such as mass or time, is called a ______ quantity.
Answer: scalar
Vectors have magnitude and direction.
1.Motion is the change in ______ of an object with time.
Answer: B
An object moves when its position changes.
2.Distance is:
Answer: A
Distance is a scalar quantity.
3.Displacement is:
Answer: D
Displacement is a vector quantity.
4.A pupil walks 3 m east and then 3 m west. What is her displacement?
Answer: D
She ends where she started, so displacement is zero (distance is 6 m).
5.Speed is defined as:
Answer: C
Speed = distance travelled ÷ time taken.
6.The SI unit of speed is:
Answer: A
Metres per second.
7.A cyclist travels 100 m in 20 s. What is her average speed?
Answer: D
Speed = 100 ÷ 20 = 5 m/s.
8.A bus travels 180 km in 3 hours. What is its average speed?
Answer: D
180 ÷ 3 = 60 km/h.
9.Velocity differs from speed because velocity:
Answer: B
Velocity is speed in a given direction.
10.Which is a vector quantity?
Answer: D
Velocity has magnitude and direction.
11.Which is a scalar quantity?
Answer: C
Speed has magnitude only.
12.An object moving at constant speed in a straight line has:
Answer: A
Its speed and direction stay the same.
13.A car whose speed increases as it moves along a straight road is:
Answer: C
Acceleration is an increase in velocity.
14.A ball rolling up a slope gradually slows down. It is:
Answer: B
Its velocity is decreasing.
15.On a distance–time graph, a horizontal line shows that the object is:
Answer: C
Its distance is not changing.
16.On a distance–time graph, a steeper straight line shows:
Answer: B
The gradient of a distance–time graph is the speed.
17.On a distance–time graph, a straight sloping line shows:
Answer: B
Equal distances in equal times mean constant speed.
18.On a speed–time graph, a straight line sloping upwards shows:
Answer: A
Speed increases by equal amounts each second.
19.On a speed–time graph, a horizontal line above the time axis shows:
Answer: D
Speed does not change.
20.A ticker-tape timer prints dots on a tape pulled by a trolley. Dots that get further apart show that the trolley is:
Answer: C
The trolley travels further between dots each time interval.
21.Evenly spaced dots on a ticker tape show that the trolley moved with:
Answer: C
Equal distances in equal times.
22.Convert 72 km/h to m/s.
Answer: B
72 × 1000 ÷ 3600 = 20 m/s.
23.A runner covers 400 m in 50 s. What is his speed?
Answer: B
400 ÷ 50 = 8 m/s.
24.How far does a car travel in 10 s at a constant speed of 15 m/s?
Answer: D
Distance = speed × time = 15 × 10 = 150 m.
25.How long does it take to walk 600 m at 1.5 m/s?
Answer: A
Time = distance ÷ speed = 600 ÷ 1.5 = 400 s.
26.The speedometer of a car shows the car's:
Answer: B
It shows the speed at that moment.
27.Average speed is calculated as:
Answer: A
It is the total distance divided by the total time taken.
28.A taxi travels 30 km in 1 hour, then 10 km in 0.5 hour. What is its average speed?
Answer: A
Total 40 km in 1.5 h = 26.7 km/h.
29.A body moving in a straight line is said to be in:
Answer: C
Linear motion is motion along a straight line.
30.A swinging pendulum is an example of:
Answer: A
It moves back and forth about a fixed point.
31.Distance is a vector quantity.
Answer: False
Distance is scalar; displacement is the vector.
32.A horizontal line on a distance–time graph means the object is not moving.
Answer: True
Its distance stays the same.
33.Velocity is speed in a stated direction.
Answer: True
Velocity is a vector.
34.An object can have a large distance travelled but zero displacement.
Answer: True
For example, running round a track back to the start.
35.Deceleration means that an object is speeding up.
Answer: False
Deceleration means slowing down.
36.Speed = distance ÷ ______.
Answer: time
Measured in m/s.
37.Distance travelled in a specified direction is called ______.
Answer: displacement
It is a vector quantity.
38.A quantity with both magnitude and direction is called a ______ quantity.
Answer: vector
Examples: velocity, displacement, force.
39.An increase in velocity with time is called ______.
Answer: acceleration
A decrease is deceleration.
40.The gradient of a distance–time graph gives the ______.
Answer: speed
A steeper line means higher speed.
1.A force is:
Answer: C
A force is a push or pull acting on an object.
2.The SI unit of force is the:
Answer: C
Named after Isaac Newton.
3.A force can:
Answer: D
Forces can start, stop, speed up, slow down, turn or deform objects.
4.Force is measured using a:
Answer: B
A spring balance stretches in proportion to the force.
5.Weight is:
Answer: C
W = mg, measured in newtons.
6.What is the weight of a 5 kg bag on Earth (g = 10 N/kg)?
Answer: A
W = mg = 5 × 10 = 50 N.
7.Which is a contact force?
Answer: B
Friction acts only when surfaces touch.
8.Which is a non-contact force?
Answer: A
Gravity acts at a distance without contact.
9.The force that keeps a book resting on a table from falling through it is the:
Answer: B
The table pushes up on the book.
10.Two forces of 6 N and 4 N act in the same direction on a box. The resultant force is:
Answer: D
Forces in the same direction add: 6 + 4 = 10 N.
11.Two forces of 6 N and 4 N act in opposite directions on a box. The resultant force is:
Answer: B
6 − 4 = 2 N, in the direction of the larger force.
12.When the forces on an object are balanced, the resultant force is:
Answer: D
Balanced forces cancel out.
13.A spring stretches 2 cm when a 4 N weight hangs on it. How far will it stretch with 10 N (within the elastic limit)?
Answer: C
Extension ∝ force: 2 cm per 4 N is 0.5 cm/N, so 10 N gives 5 cm.
14.On a force diagram, a force is shown by an arrow. The length of the arrow shows the force's:
Answer: A
The arrow points in the force's direction; its length shows its size.
15.A tug-of-war rope does not move when both teams pull with 500 N. The resultant force is:
Answer: C
Equal and opposite forces are balanced.
16.The centre of gravity of an object is the point:
Answer: B
The weight can be treated as acting at this single point.
17.The centre of gravity of a uniform metre rule is at:
Answer: D
For a uniform object it is at the geometric centre.
18.The centre of gravity of a uniform triangular sheet is at:
Answer: B
The medians of a triangle meet at its centroid.
19.The centre of gravity of an irregular flat card can be found using:
Answer: A
Lines drawn along the plumb line from two or more suspension points cross at the centre of gravity.
20.Can the centre of gravity lie outside the material of an object?
Answer: C
A ring's centre of gravity is at its centre, where there is no material.
21.An object is in stable equilibrium if, when slightly tilted, it:
Answer: A
Its centre of gravity rises when tilted, so it falls back.
22.An object is in unstable equilibrium if, when slightly tilted, it:
Answer: B
A pencil balanced on its point is unstable.
23.A ball lying on a flat table is in:
Answer: B
When rolled, it stays in its new position; its centre of gravity height doesn't change.
24.A cone resting on its base is in:
Answer: D
It returns to rest on its base when slightly tilted.
25.To make an object more stable, you should:
Answer: C
A low centre of gravity and wide base increase stability.
26.An object will topple over when:
Answer: A
The weight then produces a turning effect that tips it over.
27.Why is a bus more likely to topple when its roof rack is loaded with heavy bags?
Answer: D
A higher centre of gravity makes it less stable.
28.Racing cars are built low and wide so that they:
Answer: D
A low centre of gravity and wide wheelbase resist toppling.
29.Two forces of 3 N and 4 N act on a point at right angles to each other. What is the size of their resultant?
Answer: A
By Pythagoras: √(3² + 4²) = √25 = 5 N.
30.The resultant of two non-parallel forces can be found by drawing a:
Answer: A
The diagonal of the parallelogram gives the resultant.
31.Mass and weight mean the same thing.
Answer: False
Mass is the amount of matter (kg); weight is the gravitational force (N).
32.Friction is a non-contact force.
Answer: False
Friction needs surfaces in contact.
33.The centre of gravity of an object always lies inside the material of the object.
Answer: False
It can lie outside, as in a ring.
34.Lowering the centre of gravity makes an object more stable.
Answer: True
It must be tilted further before toppling.
35.A pencil balanced on its point is in stable equilibrium.
Answer: False
It is in unstable equilibrium.
36.The SI unit of force is the ______.
Answer: newton (N)
1 N gives 1 kg an acceleration of 1 m/s².
37.The single force that has the same effect as all the forces acting together is called the ______ force.
Answer: resultant
Balanced forces have zero resultant.
38.The point through which the whole weight of a body appears to act is its centre of ______.
Answer: gravity
Also called the centre of mass in a uniform field.
39.An object that returns to its original position after being slightly displaced is in ______ equilibrium.
Answer: stable
Its centre of gravity rises when tilted.
40.An object that stays in its new position after being displaced is in ______ equilibrium.
Answer: neutral
Like a ball on a level surface.
1.Newton's first law states that an object stays at rest or moves with constant velocity unless:
Answer: D
This is the law of inertia.
2.Inertia is the tendency of an object to:
Answer: B
More mass means more inertia.
3.Which has the greatest inertia?
Answer: B
Inertia depends on mass; the loaded lorry has the most mass.
4.Passengers in a bus jerk forward when the bus stops suddenly because of:
Answer: C
Their bodies tend to keep moving forward.
5.Seat belts protect passengers mainly because of Newton's:
Answer: D
Without a belt, a passenger keeps moving when the car stops.
6.Newton's second law states that the acceleration of an object is:
Answer: D
F = ma.
7.The equation for Newton's second law is:
Answer: C
Force = mass × acceleration.
8.A resultant force of 20 N acts on a 4 kg trolley. What is its acceleration?
Answer: B
a = F/m = 20 ÷ 4 = 5 m/s².
9.What force is needed to give a 1000 kg car an acceleration of 2 m/s²?
Answer: A
F = ma = 1000 × 2 = 2000 N.
10.A force of 30 N gives a box an acceleration of 3 m/s². What is the box's mass?
Answer: A
m = F/a = 30 ÷ 3 = 10 kg.
11.If the same force acts on a bigger mass, the acceleration will be:
Answer: A
a = F/m; a larger mass gives a smaller acceleration.
12.1 newton is the force that gives a mass of 1 kg an acceleration of:
Answer: B
1 N = 1 kg × 1 m/s².
13.Newton's third law states that:
Answer: A
Forces always come in equal and opposite pairs acting on different bodies.
14.When you push against a wall, the wall:
Answer: D
This is Newton's third law.
15.A rocket moves upwards because:
Answer: A
Action–reaction: the exhaust gases and rocket push on each other.
16.When a gun is fired, it recoils (moves backwards). This is explained by Newton's:
Answer: B
The gun pushes the bullet forward; the bullet pushes the gun back.
17.When you swim, you push water backwards. The water pushes you:
Answer: C
The reaction from the water drives you forward.
18.Action and reaction forces:
Answer: A
They act on two different objects.
19.A car moving at constant velocity on a straight road has:
Answer: A
By the first law, constant velocity means balanced forces.
20.The driving force on a 1200 kg car is 3000 N and the friction is 600 N. What is its acceleration?
Answer: B
Resultant = 3000 − 600 = 2400 N; a = 2400 ÷ 1200 = 2 m/s².
21.A tablecloth can be pulled quickly from under dishes without moving them much because of:
Answer: B
The dishes resist the sudden change in motion.
22.Shaking a wet umbrella removes water because:
Answer: C
The drops keep moving and leave the umbrella.
23.A horse pulls a cart forward. According to the third law, the cart:
Answer: D
The pair of forces is equal and opposite.
24.In space, a spacecraft with its engines switched off and no forces acting will:
Answer: A
By the first law, with no resultant force its velocity does not change.
25.A 50 kg girl on roller skates pushes a wall with 100 N. Her acceleration away from the wall is:
Answer: C
The wall pushes her with 100 N: a = 100 ÷ 50 = 2 m/s².
26.A lorry and a car have the same engine force. The car accelerates more because it has:
Answer: D
a = F/m: less mass, more acceleration.
27.Which law explains why it is harder to push a full wheelbarrow than an empty one to the same acceleration?
Answer: C
A bigger mass needs a bigger force for the same acceleration.
28.A ball is thrown in a straight line in space far from any planet. Its path will be:
Answer: D
With no forces, it moves in a straight line at constant speed.
29.An astronaut of mass 70 kg goes to the Moon, where g is about 1.6 N/kg. His mass on the Moon is:
Answer: C
Mass does not change from place to place.
30.The astronaut above (70 kg) has a weight on the Moon (g = 1.6 N/kg) of:
Answer: B
W = mg = 70 × 1.6 = 112 N.
31.Newton's first law is also called the law of inertia.
Answer: True
It describes how objects resist changes in motion.
32.A heavier object has less inertia than a lighter one.
Answer: False
More mass means more inertia.
33.Action and reaction forces act on the same object.
Answer: False
They act on two different objects.
34.F = ma means a bigger force on the same mass gives a bigger acceleration.
Answer: True
Acceleration is proportional to force.
35.An object moving at constant velocity has no resultant force on it.
Answer: True
Balanced forces give constant velocity.
36.The tendency of an object to resist a change in its motion is called ______.
Answer: inertia
It depends on mass.
37.Newton's second law can be written as F = ______.
Answer: ma
Force = mass × acceleration.
38.For every action there is an equal and opposite ______.
Answer: reaction
This is Newton's third law.
39.The force of gravity acting on an object is its ______.
Answer: weight
W = mg.
40.The weight of a 1 kg mass on Earth is about 10 ______.
Answer: N (newtons)
W = mg = 1 × 10 = 10 N.
1.Work is done when a force:
Answer: A
W = F × d.
2.The unit of work and energy is the:
Answer: B
1 J = 1 N × 1 m.
3.A boy pushes a box with a force of 20 N for 3 m. How much work does he do?
Answer: D
W = F × d = 20 × 3 = 60 J.
4.How much work is done lifting a 10 kg bag up 1.5 m? (g = 10 N/kg)
Answer: C
W = mgh = 10 × 10 × 1.5 = 150 J.
5.Energy is:
Answer: B
Energy is measured in joules.
6.The energy of a moving object is called:
Answer: C
KE = ½mv².
7.A book on a high shelf has energy because of its position. This energy is:
Answer: D
PE = mgh.
8.Energy stored in a battery is:
Answer: C
Chemical reactions release it as electrical energy.
9.What is the kinetic energy of a 4 kg trolley moving at 2 m/s?
Answer: C
KE = ½ × 4 × 2² = 8 J.
10.What is the potential energy of a 2 kg stone 10 m above the ground? (g = 10 N/kg)
Answer: D
PE = mgh = 2 × 10 × 10 = 200 J.
11.In an electric fan, electrical energy is mainly changed into:
Answer: C
The motor turns the blades.
12.In a radio, electrical energy is changed into:
Answer: B
The loudspeaker produces sound.
13.When you burn charcoal, chemical energy is changed into:
Answer: A
Burning releases heat and light.
14.The law of conservation of energy states that energy:
Answer: B
The total amount of energy stays the same.
15.Power is:
Answer: D
P = W/t.
16.The unit of power is the:
Answer: D
1 W = 1 J/s.
17.A machine does 1200 J of work in 4 s. What is its power?
Answer: B
P = 1200 ÷ 4 = 300 W.
18.A 40 W bulb is switched on for 10 s. How much energy does it use?
Answer: D
E = Pt = 40 × 10 = 400 J.
19.Which of these is a renewable energy source?
Answer: A
Sunlight is continually replaced.
20.Which of these is a non-renewable energy source?
Answer: A
Coal took millions of years to form and will run out.
21.Rwanda produces much of its electricity from:
Answer: A
Rivers and Lake Kivu methane are important local sources.
22.Biogas is produced from:
Answer: A
Bacteria break down organic waste, producing methane.
23.A machine that changes kinetic energy into electrical energy is a:
Answer: B
A bicycle dynamo is a small generator.
24.A solar panel changes:
Answer: A
Solar cells convert sunlight into electricity.
25.A girl does 3000 J of work climbing stairs in 10 s. What is her power?
Answer: A
P = 3000 ÷ 10 = 300 W.
26.If no work is done on an object, the energy transferred to it is:
Answer: C
Work done = energy transferred.
27.When a ball falls from a height, its:
Answer: B
It loses height and gains speed.
28.Which device changes electrical energy into heat energy?
Answer: B
Cookers, kettles and irons produce heat.
29.Energy wasted in machines is mostly in the form of:
Answer: C
Friction converts useful energy into heat.
30.A man pushes a car with 400 N but the car does not move. The work he does on the car is:
Answer: D
There is no movement, so no work is done on the car.
31.Work is done only when a force moves an object.
Answer: True
W = F × d; no distance, no work.
32.Power is measured in joules.
Answer: False
Power is measured in watts.
33.Energy can change from one form to another.
Answer: True
For example, chemical to electrical in a battery.
34.Coal is a renewable source of energy.
Answer: False
Coal is non-renewable.
35.A moving car has kinetic energy.
Answer: True
All moving objects have kinetic energy.
36.The ability to do work is called ______.
Answer: energy
Measured in joules.
37.Work done per second is called ______.
Answer: power
Measured in watts.
38.Energy due to height above the ground is called gravitational ______ energy.
Answer: potential
PE = mgh.
39.Energy sources that are naturally replaced, such as wind and sunlight, are called ______ sources.
Answer: renewable
They will not run out.
40.Work = force × ______.
Answer: distance (moved in the direction of the force)
W = F × d.
1.Temperature is a measure of:
Answer: C
Temperature shows the degree of hotness.
2.Heat is:
Answer: B
Heat is energy in transit, measured in joules.
3.The SI unit of heat is the:
Answer: D
Heat is energy, so it is measured in joules.
4.Temperature is measured with a:
Answer: C
Common thermometers use mercury or alcohol.
5.The lower fixed point on the Celsius scale is the:
Answer: A
Pure melting ice is 0 °C.
6.The upper fixed point on the Celsius scale is the:
Answer: D
Steam from boiling water at standard pressure is 100 °C.
7.Normal human body temperature is about:
Answer: D
A clinical thermometer is centred on about 37 °C.
8.A clinical thermometer has a narrow constriction (kink) in its tube so that:
Answer: A
The thread stays at the highest reading until shaken down.
9.Alcohol is used in thermometers for very cold places because alcohol:
Answer: B
Mercury freezes at about −39 °C.
10.Mercury is used in thermometers because it:
Answer: B
These properties give accurate readings.
11.Convert 25 °C to kelvin.
Answer: C
T = 25 + 273 = 298 K.
12.Most substances, when heated:
Answer: D
Particles move more and take up more space.
13.Gaps are left between sections of railway lines to:
Answer: A
Without gaps the rails would buckle.
14.Water is unusual because between 0 °C and 4 °C it:
Answer: A
This anomalous expansion means water is densest at 4 °C.
15.The kinetic theory of matter states that matter is made of tiny particles that are:
Answer: C
Particles are in constant motion.
16.The three common states of matter are:
Answer: A
Matter exists mainly as solid, liquid or gas.
17.In a solid, the particles:
Answer: C
Strong forces hold them in a fixed arrangement.
18.In a liquid, the particles:
Answer: A
This is why liquids flow and take the shape of their container.
19.In a gas, the particles:
Answer: B
Gases fill any container they are put in.
20.Which state of matter has a fixed shape and a fixed volume?
Answer: A
Solids keep both shape and volume.
21.Which state has a fixed volume but no fixed shape?
Answer: B
Liquids take the shape of their container.
22.Which state has neither a fixed shape nor a fixed volume?
Answer: D
Gases spread out to fill the container.
23.Gases can be compressed easily because:
Answer: D
Particles can be pushed closer together.
24.Brownian motion is the random movement of tiny particles such as smoke or pollen grains, caused by:
Answer: B
It is evidence that molecules are moving.
25.Diffusion is:
Answer: A
For example, a smell spreading through a room.
26.On the Fahrenheit scale, pure water boils at:
Answer: C
Water freezes at 32 °F and boils at 212 °F.
27.Convert 20 °C to degrees Fahrenheit. (°F = 9/5 × °C + 32)
Answer: B
°F = 9/5 × 20 + 32 = 36 + 32 = 68 °F.
28.On the Réaumur scale, the boiling point of pure water is:
Answer: A
Water freezes at 0 °Re and boils at 80 °Re.
29.A thermometric property is a physical property that:
Answer: C
Examples: expansion of a liquid, resistance of a wire.
30.Matter is anything that:
Answer: B
Solids, liquids and gases are all matter.
31.Heat and temperature are the same thing.
Answer: False
Heat is energy; temperature measures how hot something is.
32.Water is densest at 4 °C.
Answer: True
This is due to the anomalous expansion of water.
33.Particles in a gas are closer together than particles in a solid.
Answer: False
Gas particles are far apart; solid particles are closely packed.
34.Brownian motion is evidence that particles of matter are moving.
Answer: True
Visible particles are pushed by invisible moving molecules.
35.Liquids have a fixed shape.
Answer: False
Liquids take the shape of their container.
36.The instrument used to measure temperature is called a ______.
Answer: thermometer
Mercury and alcohol are common liquids used.
37.A strip made of two different metals that bends when heated is called a ______ strip.
Answer: bimetallic
Used in thermostats.
38.The random movement of small particles caused by collisions with molecules is called ______ motion.
Answer: Brownian
Named after Robert Brown.
39.The theory that matter is made of moving particles is called the ______ theory.
Answer: kinetic (kinetic molecular)
Kinetic means related to motion.
40.On the Fahrenheit scale, pure water freezes at ______ °F.
Answer: 32
And boils at 212 °F.
1.Electrostatics is the study of:
Answer: A
Static means at rest; electrostatics deals with stationary charges.
2.The two kinds of electric charge are:
Answer: C
Protons are positive and electrons are negative.
3.The SI unit of electric charge is the:
Answer: C
Charge is measured in coulombs (C).
4.The charge on one electron is about:
Answer: B
e = 1.6 × 10⁻¹⁹ C; the electron's charge is −e.
5.An atom is electrically neutral because it has:
Answer: A
The positive and negative charges cancel.
6.When a plastic ruler is rubbed with a dry cloth and becomes negatively charged, it has:
Answer: D
Only electrons move during charging by friction.
7.In the example above, the cloth becomes:
Answer: B
The cloth lost electrons to the ruler, so it is positive.
8.Charging a body by rubbing it with another material is called charging by:
Answer: B
Electrons are transferred from one material to the other.
9.Charging by contact (conduction) happens when:
Answer: D
Charge flows from the charged body to the neutral one.
10.Charging by induction means:
Answer: C
The nearby charge separates charges in the conductor; earthing then leaves it charged.
11.In charging by induction, the charge left on the conductor is:
Answer: A
Earthing removes the like charges, leaving opposite charge.
12.The first law of electrostatics states that:
Answer: A
Positive repels positive; positive attracts negative.
13.A positively charged rod is brought near a negatively charged balloon. The balloon will be:
Answer: B
Unlike charges attract.
14.Coulomb's law states that the force between two point charges is:
Answer: C
F = kq₁q₂/r².
15.In Coulomb's law F = kq₁q₂/r², the constant k is about:
Answer: D
k = 1/(4πε₀) ≈ 9 × 10⁹ N m²/C².
16.If the distance between two charges is doubled, the force between them becomes:
Answer: D
F ∝ 1/r², so doubling r gives 1/4 of the force.
17.If one of the two charges is doubled (distance unchanged), the force:
Answer: D
F is proportional to the product q₁q₂.
18.Two charges of 1 × 10⁻⁶ C each are 0.1 m apart. What is the force between them? (k = 9 × 10⁹ N m²/C²)
Answer: A
F = 9 × 10⁹ × 10⁻⁶ × 10⁻⁶ ÷ 0.01 = 0.9 N.
19.Which of these is a good conductor of electricity?
Answer: C
Metals have free electrons that move easily.
20.Which of these is an electrical insulator?
Answer: A
Insulators have very few free electrons.
21.Conductors allow charge to flow because they have:
Answer: B
Free electrons carry charge through the material.
22.Electrical wires are covered with plastic because plastic:
Answer: B
The insulation prevents contact with the live conductor.
23.A charged comb picks up small pieces of paper because:
Answer: D
Induced charges attract the paper to the comb.
24.A gold-leaf electroscope is used to:
Answer: C
Its leaf rises when the instrument is charged.
25.When a charged rod touches the cap of a neutral gold-leaf electroscope, the leaf rises because:
Answer: B
Like charges on the leaf and stem repel each other.
26.Earthing a charged conductor means:
Answer: C
The Earth can accept or supply electrons, neutralising the conductor.
27.You may feel a small shock after walking on a nylon carpet and touching a metal door handle because:
Answer: A
This is a discharge of static electricity.
28.Lightning is a large discharge of:
Answer: B
Charge separation in clouds builds up very high voltages.
29.A body that has more electrons than protons is:
Answer: A
Extra electrons give a negative charge.
30.Charge is neither created nor destroyed during charging. Rubbing only:
Answer: D
This is the conservation of charge.
31.Like charges attract each other.
Answer: False
Like charges repel; unlike charges attract.
32.During charging by friction, it is electrons that move from one body to another.
Answer: True
Protons stay fixed in the nuclei.
33.Copper is a good insulator.
Answer: False
Copper is a good conductor.
34.The force between two charges decreases as the distance between them increases.
Answer: True
F ∝ 1/r².
35.A neutral atom has equal numbers of protons and electrons.
Answer: True
The charges balance.
36.The SI unit of electric charge is the ______.
Answer: coulomb (C)
Named after Charles-Augustin de Coulomb.
37.Charging a body by bringing a charged object near it without touching is called charging by ______.
Answer: induction
Earthing then leaves an opposite charge.
38.Materials that allow electric charge to flow easily are called ______.
Answer: conductors
Metals are good conductors.
39.An instrument used to detect electric charge using a thin metal leaf is a gold-leaf ______.
Answer: electroscope
The leaf rises when charged.
40.Coulomb's law: F = kq₁q₂ ÷ ______.
Answer: r2 (r², distance squared)
The force is inversely proportional to the square of the distance.
1.Electric current is the rate of flow of:
Answer: D
I = Q/t.
2.The SI unit of electric current is the:
Answer: A
1 A = 1 C/s.
3.A charge of 60 C flows through a lamp in 20 s. What is the current?
Answer: A
I = Q/t = 60 ÷ 20 = 3 A.
4.Potential difference (voltage) between two points is the:
Answer: B
V = W/Q, measured in volts.
5.The SI unit of potential difference is the:
Answer: D
1 V = 1 J/C.
6.In a simple electric circuit, the cell (battery) provides:
Answer: A
The cell is the source of electrical energy.
7.A switch in a circuit is used to:
Answer: C
When the switch is open, no current flows.
8.Current can flow in a circuit only when the circuit is:
Answer: A
A complete path is needed.
9.In a circuit diagram, a long thin line next to a short thick line represents a:
Answer: C
The long line is the positive terminal.
10.Conventional current flows from:
Answer: C
Electrons actually flow the opposite way, from negative to positive.
11.Current is measured with an:
Answer: D
The ammeter must carry the same current as the component.
12.Potential difference is measured with a:
Answer: B
The voltmeter is connected across the component.
13.Which is a safety precaution when handling electrical appliances?
Answer: B
Overloading can overheat wires and cause fires.
14.Why should you never touch electrical switches with wet hands?
Answer: D
Wet skin lets current pass more easily through the body.
15.A fuse in a plug protects the circuit by:
Answer: A
It uses the heating effect of current.
16.Electrical resistance is:
Answer: C
R = V/I, measured in ohms.
17.The SI unit of resistance is the:
Answer: D
1 Ω = 1 V/A.
18.The resistance of a wire increases when the wire is:
Answer: B
R = ρL/A: longer wires and smaller cross-sections give more resistance.
19.Resistivity of a material:
Answer: B
Resistivity ρ is measured in ohm-metres (Ω m).
20.The resistance R of a wire of length L, cross-sectional area A and resistivity ρ is:
Answer: D
R = ρL/A.
21.A copper wire 2 m long has a cross-sectional area of 1.0 × 10⁻⁶ m². The resistivity of copper is 1.7 × 10⁻⁸ Ω m. What is its resistance?
Answer: A
R = ρL/A = 1.7 × 10⁻⁸ × 2 ÷ 1.0 × 10⁻⁶ = 0.034 Ω.
22.Ohm's law states that, at constant temperature:
Answer: C
V = IR.
23.A 12 V battery drives a current of 3 A through a resistor. What is its resistance?
Answer: A
R = V/I = 12 ÷ 3 = 4 Ω.
24.A current of 2 A flows through a 6 Ω resistor. What is the voltage across it?
Answer: B
V = IR = 2 × 6 = 12 V.
25.A 9 V supply is connected across an 18 Ω resistor. What current flows?
Answer: A
I = V/R = 9 ÷ 18 = 0.5 A.
26.The graph of current against voltage for a resistor that obeys Ohm's law is:
Answer: B
Current is proportional to voltage.
27.An electric iron and a kettle use the:
Answer: B
The current heats the element.
28.An electric bell works because of the:
Answer: C
An electromagnet pulls the hammer onto the gong.
29.Electroplating a spoon with silver uses the:
Answer: D
Current through an electrolyte deposits metal.
30.A filament lamp gives light because the current:
Answer: C
The white-hot filament glows.
31.An ammeter is connected in parallel with a component.
Answer: False
An ammeter is connected in series.
32.Ohm's law can be written as V = IR.
Answer: True
Voltage = current × resistance.
33.A longer wire of the same material and thickness has a greater resistance.
Answer: True
Resistance is proportional to length.
34.It is safe to repair electrical appliances while they are plugged in.
Answer: False
Always switch off and unplug first.
35.Resistivity depends on the length of the wire.
Answer: False
Resistivity depends only on the material; resistance depends on length.
36.The rate of flow of electric charge is called electric ______.
Answer: current
I = Q/t.
37.The SI unit of potential difference is the ______.
Answer: volt (V)
1 V = 1 J/C.
38.An instrument used to measure potential difference is a ______.
Answer: voltmeter
Connected in parallel.
39.The opposition to the flow of current is called ______.
Answer: resistance
Measured in ohms.
40.A safety device that melts when the current is too large is a ______.
Answer: fuse
It breaks the circuit.
1.A luminous object is one that:
Answer: C
The Sun, a candle flame and a lit bulb are luminous.
2.Which of these is a natural source of light?
Answer: C
The Sun is a natural source; the others are artificial.
3.The Moon is a non-luminous object. We see it because it:
Answer: C
Non-luminous objects are seen by reflected light.
4.A ray of light is:
Answer: C
A ray shows the direction of travel of light.
5.A collection of light rays is called a:
Answer: D
Beams can be parallel, converging or diverging.
6.The beam of light from a car headlamp is mostly:
Answer: A
Headlamps use curved mirrors to produce a nearly parallel beam.
7.Light from a candle flame spreads out in all directions. Its rays are:
Answer: B
Rays spread out from a point source.
8.A transparent material is one that:
Answer: B
Clear glass and water are transparent.
9.Frosted glass and greaseproof paper are:
Answer: A
They let some light through but scatter it, so images are blurred.
10.Wood, metal and brick are:
Answer: B
Opaque materials do not let light through.
11.Rectilinear propagation of light means that light:
Answer: A
This explains shadows and the pinhole camera.
12.Shadows are formed because:
Answer: D
Light cannot reach the region behind the opaque object.
13.A shadow formed by a small (point) source of light is:
Answer: D
A point source gives a sharp shadow with no penumbra.
14.With an extended (large) light source, the shadow has a dark centre called the umbra and a partly lit edge called the:
Answer: A
The penumbra receives light from part of the source.
15.A solar eclipse occurs when:
Answer: A
The Moon's shadow falls on the Earth.
16.A lunar eclipse occurs when:
Answer: A
The Earth's shadow falls on the Moon.
17.The image formed by a pinhole camera is:
Answer: A
Rays cross at the pinhole, so the image is inverted.
18.The magnification of a pinhole camera is given by:
Answer: B
m = h_i/h_o = v/u.
19.A tree 10 m tall is 20 m from a pinhole camera. The screen is 10 cm (0.1 m) behind the pinhole. How tall is the image?
Answer: B
h_i = h_o × v/u = 10 × 0.1 ÷ 20 = 0.05 m = 5 cm.
20.If the pinhole of a pinhole camera is made larger, the image becomes:
Answer: A
More light enters, but the larger hole lets many overlapping images form.
21.Moving the screen of a pinhole camera further from the pinhole makes the image:
Answer: D
Image size is proportional to the image distance v.
22.The first law of reflection states that the incident ray, the reflected ray and the normal:
Answer: D
They lie in one plane at the point of incidence.
23.The second law of reflection states that:
Answer: B
Both angles are measured from the normal.
24.A ray strikes a plane mirror at 35° to the normal. What is the angle of reflection?
Answer: C
Angle of reflection = angle of incidence = 35°.
25.A ray makes an angle of 30° with the surface of a plane mirror. What is the angle of incidence?
Answer: C
Angles are measured from the normal: 90° − 30° = 60°.
26.Reflection from a smooth, shiny surface such as a mirror, which gives a clear image, is called:
Answer: D
Parallel rays stay parallel after reflection.
27.Reflection from a rough surface such as paper, which scatters light in many directions, is called:
Answer: B
This is why we can see a page from any direction.
28.The image formed by a plane mirror is:
Answer: D
It appears as far behind the mirror as the object is in front.
29.A girl stands 2 m in front of a plane mirror. How far is she from her image?
Answer: B
The image is 2 m behind the mirror, so 2 + 2 = 4 m from her.
30.Two plane mirrors are inclined at 60° to each other. How many images of an object between them are formed? (n = 360/θ − 1)
Answer: C
n = 360 ÷ 60 − 1 = 5.
31.Light travels in straight lines.
Answer: True
This is rectilinear propagation of light.
32.Frosted glass is a transparent material.
Answer: False
Frosted glass is translucent.
33.The image in a pinhole camera is upright.
Answer: False
It is inverted because rays cross at the pinhole.
34.The image in a plane mirror is laterally inverted.
Answer: True
Left and right appear swapped.
35.Two parallel plane mirrors facing each other can form a very large (infinite) number of images.
Answer: True
Light is reflected back and forth many times.
36.An object that produces its own light is called a ______ object.
Answer: luminous
For example, the Sun.
37.Materials that do not allow any light to pass through are called ______.
Answer: opaque
Wood and metal are opaque.
38.The region of total shadow is called the ______.
Answer: umbra
No light from the source reaches it.
39.The angle of incidence is equal to the angle of ______.
Answer: reflection
Second law of reflection.
40.A simple box with a small hole that forms an inverted image on a screen is a ______ camera.
Answer: pinhole
It shows that light travels in straight lines.