It' i's revision time, take Physics

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It' i's revision time, take Physics - GCE O-Level 2020.

41/41 MCQs for:

GCE O-Level 2020.

The base unit of length is:

Mm.

km.

cm.

Which of the following is NOT a physical quantity?

3 seconds.

joule.

metre.

100.

A body is taken from the equator to the North Pole.

Its mass remains constant but its weight increases.

Its mass increases and its weight remains constant.

Its mass decreases and its weight remains constant.

Its mass and its weight both remain constant.

A ball is thrown downward at 5 m/s from a roof m high. Its velocity when it reaches the ground is:

20 m/s.

13 m/s.

15 m/s.

14 m/s.

An experiment is carried out to determine the acceleration of free fall by timing the direct fall of a steel ball, from an initial velocity of zero through a given height.

The equation of motion that is used to process the data collected in the experiment is:

S = ½ (u + v)t.

v² = u² + 2as.

V = u + at.

S = ut + ½ at².

Energy is defined as:

Ability to do work.

energy output / energy input.

work input / work output.

Rate of doing work.

A stone of mass 0.2 kg is moving with a velocity of 20 m/s. How much kinetic energy does the stone possess?

2 J.

4 J.

40 J.

20 J.

Which of the following energy sources are all renewable sources?

Geothermal, coal, wind.

Wood, wave, animal waste.

Sun, Uranium, tides.

Petrol, flowing water, Sun.

A machine has a velocity ratio of 9 and needs an effort of 10 N to lift a load of 50 N. The efficiency of the machine is:

20.0%.

55.6%.

66.7%.

11.1%.

When a trumpet and a guitar are used to play the same musical note a difference is noticed. This difference is due to the:

frequency.

pitch.

overtones.

fundamental.

An object is placed at a point beyond 2F from a converging lens. The image formed is:

Virtual, magnified, erect.

Real, diminished, inverted.

Real, magnified, erect.

Real, same size, inverted.

The primary coil of a transformer is often wound on the secondary coil so as to prevent:

flux linkage losses.

eddy current losses.

high resistance losses.

hysteresis losses.

The numerical value of absolute zero in degree Celsius is:

100.

-273.

273.

When a radioactive atom undergoes beta decay:

the proton number increases by 1 and the nucleon number remains the same.

the proton number decreases by 1 and the nucleon number remains the same.

the proton number remains the same and the nucleon number increases by 1.

the proton number remains the same and the nucleon number decreases by 1.

A cellulose acetate rod rubbed with cloth:

gains electrons and becomes negatively charged.

losses protons and becomes negatively charged.

gains protons and becomes positively charged.

losses electrons and becomes positively charged.

Electromotive force (EMF) is measured in:

joules.

volts.

amperes.

Newtons.

The effective resistance of a 12Ω resistor and a 6Ω resistor connected in parallel is:

6Ω.

4Ω.

¼ Ω.

18Ω.

A 2400 W electric iron is used at maximum output for 6 hours in a month. If the cost of a unit of electricity is 60 FCFA, how much will the user pay as electricity bill for that month?

1440 FCFA.

8640 FCFA.

360 FCFA.

864 FCFA.

If the distance between two charges Q₁, and Q₂ is doubled, the electrostatic force of repulsion between them will:

reduce.

remain the same.

double.

increase.

An open can containing a little water is heated until the water boils. The can is then closed tightly and cold water poured on the can. The sides of the can collapse because:

the water outside cools rapidly.

the water inside cools rapidly.

the external pressure increases rapidly.

the internal pressure reduces rapidly.

Which of the following instruments is an application of Hooke's Law?

Manometer.

Newton metre.

Beam balance.

Bourdon gauge.

When a bucket full of water is being pulled out of a well, it appears lighter when it is still in the water than when it is out of water. The ‘apparent lightness’ is caused by:

tension.

weight.

friction.

upthrust.

Which of the following physical quantities has newton-metre as the unit?

Power.

Work.

Pressure.

Momentum.

A ripe mango falls from a tree 32 m tall. If its initial velocity is zero, the time it takes to reach the ground is:

2.5 s.

1.8 s.

6.4 s.

64.0 s.

The figure shows how the displacement of an object in the direction of a force applied varies with the force. The shaded area under the graph represents:

Work.

Power.

Momentum.

Moment.

The best reason why aluminium is often preferred to steel in the construction of aircraft is that aluminium:

Does not rust.

Has a lower density.

Has a higher mass per unit length.

Has a shiny appearance.

An electromagnetic radiation which is emitted from the nucleus of an atom is:

infrared radiation.

gamma radiation.

alpha radiation.

X-ray.

It is not possible to predict which atom of a particular radioactive sample will decay. This is because:

radioactive decay is a spontaneous process.

radioactive decay is a random process.

the half-life a particular radioisotope is constant.

during radioactive decay the mass of the radioactive isotope reduces.

The specific heat capacity of a material depends.

nature of the material.

thermal energy gained by the material.

mass of the material.

the:

When one end of an iron rod is held in the hand and the other end is inserted into a flame and left there for a few minutes, heat energy soon reaches the hand by:

convection and radiation.

conduction.

radiation.

convection.

On a certain filament bulb is written 220 V, 80 W. The resistance offered by the filament when a current of 11A flows through the main supply is:

605Ω.

20Ω.

3Ω.

364Ω.

Which of the following elements should be added to germanium to produce a p-type semiconductor?

Boron.

Silicon.

Phosphorus.

Copper.

Which of the following quantities determines the loudness of a sound?

Frequency.

Amplitude.

Wavelength.

Overtones.

The critical angle for a ray of light incident in water at a water-air boundary is 47.8°. The refractive index of water is:

1.4.

1.9.

1.0.

0.7.

When the net force acting on an object reduces, the acceleration of the object:

doubles.

increases.

reduces.

remains the same.

Which of the graphs in the figure represents a velocity-time graph for an object accelerating uniformly from rest?

Heavy duty vehicles usually have large and broad tyres. Of what advantage is this?

To exert a small force on the ground.

To exert a small pressure on the road.

To reduce the stability of the car.

To support the heavy weight of the vehicle.

The Electromotive force of a cell is given as1.5 V. This means that the cell can supply:

1.5J of energy per coulomb of charge.

1.5 J of energy.

1.5 A of current.

1.5J of energy per ampere of current.

Which of the following devices is a rectifier?

Transformer.

Resistor.

Diode.

Rheostat.

Which of the radiations or particles below is most ionising?

Beta particles.

X-rays.

Gamma radiation.

Alpha particles.

The figure shows a rectangular coil WXYZ carrying a current and located between the pole pieces of a horse-shoe magnet. The motion of the coil WXYZ can be decreased by:

Using a larger coil.

reversing the magnetic pole pieces.

using a weaker magnet.

having fewer turns of coil.