Physics Mock 2021

WASSCE style · Study mode

Physics Mock 2021

Question 1 of 50

The lower fixed point on the Celsius scale is the

A. boiling point of water B. melting point of pure ice C. temperature of the body D. absolute zero

Question 2 of 50

The speed of sound in air is about

A. 34 m/s B. 3 × 10⁸ m/s C. 1,500 m/s D. 340 m/s

Question 3 of 50

The pitch of a note depends on its

A. speed B. amplitude C. frequency D. wavelength in vacuum only

Question 4 of 50

The unit of electrical energy used by the electricity company for billing is the

A. kilowatt-hour B. joule C. volt D. ampere

Question 5 of 50

Which material is used for the core of an electromagnet?

A. soft iron B. steel C. copper D. aluminium

Question 6 of 50

Which device detects ionising radiation?

A. Geiger–Müller tube B. voltmeter C. thermometer D. barometer

Question 7 of 50

Convert 300 K to degrees Celsius.

A. 27 °C B. 573 °C C. −27 °C D. 300 °C

Question 8 of 50

A swimming pool looks shallower than it really is because of

A. refraction B. reflection C. diffraction D. dispersion

Question 9 of 50

A wave has a period of 0.02 s. What is its frequency?

A. 50 Hz B. 0.02 Hz C. 20 Hz D. 200 Hz

Question 10 of 50

The distance between two successive crests of a wave is its

A. wavelength B. amplitude C. frequency D. period

Question 11 of 50

Three currents of 2 A, 3 A and 1 A flow into a junction. One current flows out. How large is it?

A. 6 A B. 4 A C. 2 A D. 0 A

Question 12 of 50

A car accelerates uniformly from rest to 20 m/s in 5 s. Its acceleration is

A. 0.25 m/s² B. 100 m/s² C. 4 m/s² D. 25 m/s²

Question 13 of 50

A force of 50 N moves a box 4 m in the direction of the force. The work done is

A. 12.5 J B. 200 J C. 54 J D. 46 J

Question 14 of 50

A 2 kg mass is raised 5 m (g = 10 m/s²). Its gain in potential energy is

A. 25 J B. 10 J C. 50 J D. 100 J

Question 15 of 50

Newton's third law states that

A. a body stays at rest unless acted on B. F = ma C. for every action there is an equal and opposite reaction D. energy is conserved

Question 16 of 50

Land and sea breezes are caused by

A. evaporation only B. conduction in rocks C. radiation from the moon D. convection currents

Question 17 of 50

A vacuum flask reduces heat loss by conduction and convection mainly through its

A. cork stopper only B. silvered surfaces C. vacuum between the double walls D. plastic case

Question 18 of 50

Evaporation differs from boiling because evaporation

A. needs a flame B. happens only at 100 °C C. happens throughout the liquid D. happens at any temperature from the surface

Question 19 of 50

An echo is heard 2 s after a shout towards a cliff. If sound travels at 340 m/s, how far away is the cliff?

A. 680 m B. 340 m C. 170 m D. 1,360 m

Question 20 of 50

Which electromagnetic waves have the longest wavelength?

A. ultraviolet B. X-rays C. gamma rays D. radio waves

Question 21 of 50

A concave mirror is used as a shaving mirror because, with the face close to it, it gives

A. a diminished image B. a magnified, upright image C. an inverted image D. no image

Question 22 of 50

Resistors of 2 Ω and 3 Ω are connected in parallel. What is the combined resistance?

A. 1.2 Ω B. 5 Ω C. 6 Ω D. 0.83 Ω

Question 23 of 50

What charge flows when a current of 2 A passes for 5 minutes?

A. 600 C B. 10 C C. 150 C D. 2.5 C

Question 24 of 50

A fuse should be connected in the

A. live wire B. neutral wire C. earth wire D. none of the wires

Question 25 of 50

The nucleus of ²³⁵U contains 92 protons. How many neutrons does it have?

A. 143 B. 92 C. 235 D. 327

Question 26 of 50

When a nucleus emits an alpha particle, its mass number

A. decreases by 4 B. increases by 4 C. decreases by 2 D. stays the same

Question 27 of 50

Mercury is used in thermometers partly because it

A. expands uniformly and does not wet glass B. is transparent C. freezes at 0 °C D. is a poor conductor of heat

Question 28 of 50

The critical angle of a glass is 42°. Total internal reflection occurs when light inside the glass hits the surface at

A. more than 42° B. less than 42° C. exactly 0° D. any angle

Question 29 of 50

How much heat is needed to melt 2 kg of ice at 0 °C? (Specific latent heat of fusion = 3.4 × 10⁵ J/kg)

A. 6.8 × 10⁵ J B. 1.7 × 10⁵ J C. 3.4 × 10⁵ J D. 6.8 × 10⁴ J

Question 30 of 50

In the method of mixtures, it is assumed that

A. heat lost by hot bodies equals heat gained by cold bodies B. no heat is gained C. temperature never changes D. mass changes

Question 31 of 50

A potential divider has resistors of 2 kΩ and 8 kΩ across 10 V. What is the voltage across the 8 kΩ resistor?

A. 8 V B. 2 V C. 10 V D. 5 V

Question 32 of 50

A camera lens forms an image on the sensor that is

A. real, inverted and diminished B. virtual and upright C. magnified and upright D. virtual and inverted

Question 33 of 50

The area under a velocity–time graph gives the

A. acceleration B. displacement C. force D. power

Question 34 of 50

A machine has a velocity ratio of 5 and an efficiency of 80%. Its mechanical advantage is

A. 0.16 B. 6.25 C. 4 D. 400

Question 35 of 50

A 1,000 W motor does work for 1 minute. The energy used is

A. 1,000 J B. 60,000 J C. 16.7 J D. 60 J

Question 36 of 50

The magnification of an image formed 60 cm from a lens when the object is 20 cm away is

A. 3 B. 0.33 C. 40 D. 80

Question 37 of 50

The maximum speed of a body in SHM with amplitude 0.1 m and angular frequency 10 rad/s is

A. 1 m/s B. 10 m/s C. 0.01 m/s D. 100 m/s

Question 38 of 50

The ripple in a rectified output is reduced by

A. a larger smoothing capacitor B. a smaller capacitor C. removing diodes D. higher frequency transformer only

Question 39 of 50

Using a vernier caliper, main scale 2.3 cm and vernier 6th line coincides (0.01 cm per division). The reading is

A. 2.6 cm B. 2.30 cm C. 2.36 cm D. 2.06 cm

Question 40 of 50

A lever has a load of 600 N at 0.2 m from the fulcrum. The effort needed at 1.2 m is

A. 3,600 N B. 100 N C. 600 N D. 144 N

Question 41 of 50

A pulley system of VR 5 and efficiency 60% has a mechanical advantage of

A. 5 B. 8.3 C. 3 D. 0.12

Question 42 of 50

A coil of 200 turns has its flux changed from 0.05 Wb to 0 in 0.1 s. The average induced e.m.f. is

A. 100 V B. 10 V C. 1 V D. 0.1 V

Question 43 of 50

A mass on a spring has a period of 2 s. If the mass is quadrupled, the period becomes

A. 4 s B. 8 s C. 1 s D. 2 s

Question 44 of 50

A body travels the first half of a journey at 20 m/s and the second half at 30 m/s. Its average speed is

A. 10 m/s B. 25 m/s C. 50 m/s D. 24 m/s

Question 45 of 50

A velocity–time graph rises from 0 to 20 m/s in 4 s, stays constant for 6 s, then falls to 0 in 2 s. The total distance is

A. 240 m B. 180 m C. 120 m D. 200 m

Question 46 of 50

A gun of mass 4 kg fires a 20 g bullet at 400 m/s. The recoil velocity of the gun is

A. 8 m/s B. 20 m/s C. 0.2 m/s D. 2 m/s

Question 47 of 50

A 1,200 kg car climbs a 20 m hill at constant speed in 40 s (g = 10 m/s²). The minimum power is

A. 60 kW B. 24 kW C. 600 W D. 6 kW

Question 48 of 50

An electric heater of 500 W warms 2 kg of oil by 25 K in 3 minutes. The specific heat capacity of oil is

A. 900 J/kg K B. 1,800 J/kg K C. 3,600 J/kg K D. 450 J/kg K

Question 49 of 50

A gas at 2 atm and 300 K is compressed to half its volume while its temperature rises to 450 K. Its new pressure is

A. 4 atm B. 3 atm C. 6 atm D. 1.5 atm

Question 50 of 50

A converging lens of focal length 20 cm forms a real image 60 cm from it. The object distance is

A. 60 cm B. 15 cm C. 40 cm D. 30 cm

Questions written by OtisamLMS in the style of the WASSCE. They are not WAEC past questions.