Calculate the work done when a force of 20N stretches a spring by 50mm.

• A. 0.5J
• B. 1.5J
• C. 2.0J
• D. 2.5J

The magnetic force on a charged particle moving with velocity v is

• A. proportional to both the magnitude of the charge and the velocity v
• B. independent of the magnitude of the charge
• C. proportional to the velocity v only
• D. proportional to the magnitude of the charge only

The pressure of air in a tire is \(22.5Nm^{-2}\) at 27°C. If the air in the tyre heats up to 47°C, calculate the new pressure of the air, assuming that no air leaks out and that the change in volume of the air can be neglected.

• A. \(21.10Nm^{-2}\)
• B. \(24Nm^{-2}\)
• C. \(39.07Nm^{-2}\)
• D. \(45Nm^{-2}\)

The speed of light in air is 3 x 10⁸ms^-1. What is the speed in glass with a refractive index of 1.50?

• A. 1.5 x 10⁸ms^-1
• B. 3.0 x 10⁸ms^-1
• C. 2.0 x 10⁸ms^-1
• D. 6.0 x 10⁸ms^-1

Two inductors of inductance 4 II and 8 II are arrange in series and a current of 10 A is passed through them. What is the energy stored in them?

• A) 500 J
• B) 50 J
• C) 133 J
• D) 250 J

Complementary colours are those which

• A. have the same refractive index
• B. have the same wavelength
• C. add-up to produce black light
• D. add-up to produce white light

Which of the following instruments may be used to measure relative humidity?

• A. Hydrometer
• B. Manometer
• C. Hygrometer
• D. Hypsometer

A plastic sphere floats in water with 50% of its volume submerged. if it floats in glycerine with 40% of its volume submerged,the density of the glycerine is?

• A) 1400 kgm^-3
• B) 1250 kgm^-3
• C) 500 kgm^-3
• D) 1000 kgm^-3

Palm oil from a bottle flows out more easily after it as been heated because the

• A. molecules are given potential energy during the heating
• B. friction between oil layers is reduced
• C. oil molecules force each other out
• D. adhesion between the oil molecules and those of the bottle is increased

A moving car of mass 800 kg experiences a frictional force of 200N. If it accelerates 2 ms^-2, calculate the magnitude of the force applied to the car

• A. 600N
• B. 1000N
• C. 1600N
• D. 1800N