Physics 2021

Which of the following is not an example of force?

The reason for laminating the soft iron of a transformer is to

Formation of hydrogen bubbles at the copper plate of a primary cell is called

Which of the following factors does not affect the rate of evaporation of a liquid?

The opening in the eye through which light passes to the retina is called the

A heat sensitive resistor made of a semiconductor is called a

Electric motor primarily converts

Which of the following statements about the molecules of solids and liquids is correct?

The distance between a node and its adjacent antinode of a transverse wave is equal to

Which of the sketched graphs below illustrates the correct variation of the gravitational force, Fg, between two objects and the distance, d, between their centres?

Which of the following actions will increase the capacitance of a parallel plate capacitor?
I. Decreasing the distance between the plates
II. Increasing the distance between the plates
III. Increasing the area of the plates overlap
IV. Avoiding the use of dielectric between the plates

A metallic sphere is heated from 27°C to 200°C without change of state. Which of the following changes would have resulted from the heating?

The acceleration of a moving object can be determined from the

A student wishes to measure the potential difference across a resistor, R. She has a galvanometer, G and some connecting wires, what else does she need?

The handle of a crew jack is 35cm long and the pitch of the screw is 0.5cm. What force must be applied at the end of the handle to lift a load of 2000N if the efficiency of the jack is 30%?
π = 22/7

The inductive reactance in a circuit of frequency 100Hz is 1Ω. Calculate the inductance of the inductor.
π = 3.14

The diagram below illustrates the velocity-time graph of a body. Calculate the distance covered by the body during the motion.

An atom that emits an α – particle

Which of the following units is equivalent to the unit of electric current?

A ball is swung in a horizontal circle of centre O with a constant speed. What is the direction of its acceleration?

Which of the following statements is an effect of compressing gas molecules at constant temperature?

The diagram below is an illustration of an a.c. circuit. Calculate the reactance of the capacitor.

A current of 2A passes through a wire of resistance 4Ω for 3 minutes. Calculate the energy lost.

Which of the following statements about the universal gravitational constant, G, is true?

From the wave diagram, determine the amplitude and wavelength of the wave.

Calculate the wave speed given the period is 0.125 s.

Which of the following curved surfaces will produce a real image?
I. Concave mirror
II. Convex mirror
III. Diverging lens
IV. Converging lens

The components of vectors Q and R are (-3.0, 5.5) and (9.2, 4.4), respectively. Determine the components of Q+R.

Which of the arrangements of radiations below shows decreasing order of wavelength?

An electric pressing iron is connected to the mains using an insulated wire. After some minutes, the wire becomes very hot. The heat generated in the wire can be minimized by replacing the wire with one of

In the diagram below, a bulb is lit by drawing 2.0A from 440V a.c. Calculate the cost of keeping the bulb on for two days at $0.40 per kilowatt-hour.

A wire of cross-sectional area 2π x 10^-8m² and resistivity 1.1 x 10^-8Ωm, has a resistance of 21Ω. Calculate the length of the wire.

Which of the following statements best describes the particles in a solid at room temperature? They are

A man weighing 200N runs up a staircase in 5s. If the height of the staircase is 9m, calculate the power of the man.

A rotating disc contains a set of holes in a circle. An air jet is directed onto the holes and a note of frequency 480Hz is produced. If the number of holes is 20, calculate the speed of rotation of the disc.

A force of 10N, acting continuously, increases the kinetic energy of an object from 20J to 60J. Find the distance moved by the object.

An electric circuit consists of a resistor, a battery and a key. If the voltage of the battery is increased, there would be an increase in the

A radioactive material has a half-life of 1.0 hour. If 200.0g of it was present at 6a.m. on a certain day, how many grams will have decayed by 9a.m. on the same day?

The following statements about a loudspeaker are correct except

An ice cube has a mass of 20g at -5⁰C. Calculate the energy required to raise its temperature to 0⁰C. [Specific heat capacity of ice 2.1jg^-10C^-1]

A stone is thrown horizontally with an initial velocity of 15ms^-1 from a tower 20m high. How long does it take to reach the ground?
g = 10ms^-2

Which of the following statements is not a characteristic of a plane progressive wave?

The electrons in a cathode-ray tube are produced by

Which of the following statements about distance and displacement is not correct?

A note produced by an instrument is distinguished from a similar note produced by another instrument by the

According to Pascal’s principle, the pressure in a fluid is always

Which of the following set of quantities have members which are all vectors?

If the relative humidity of the atmosphere increases, the rate of evaporation of sweat from the human body

Which of the following factors is not among those that determine the resistance of a wire? Its

Which of the following scientists suggested that moving particles exhibit wave properties?