Physics Past Questions and Answers

Which of the following statements is true? The frequency of a vibrating string is

A Proportional to its length
B Inversely proportional to the tension within it
C Proportional to the aptitude of vibration
D Inversely proportional to its cross-section
E Proportional to the square root of the tension within it

Question 82:

An air bubble rises from the bottom to the top of a water dam which is 40m deep. The volume of the bubble just below the surface is 2.5cm3. Find its volume at the bottom of the dam, if atmospheric pressure is equivalent to 10m water

A 0.0cm3
B 2.0cm3
C 1.6cm3
D 0.625cm3
E 0.5cm3

Question 83:

Which of the following electromagnetic waves has the shortest wavelength?

A Radio waves
B X-rays
C Infra-red
D Blue light
E Ultraviolet

Question 84:

All the heat generated in a 5 ohms resistor by 2A flowing for 30 seconds is used to evaporate 5g of a liquid at its boiling point. Which of the following is the correct value of the specific latent heat of the liquid?

A 120J
B 60Jg-1
C 120Jg-1
D 1500J
E 1500Jg-1

Question 85:

The speed of light in air is 3 x 108ms-1. If the refractive index of light from air-to-water is \(\frac{4}{3}\), then which of the following is the correct value of the speed of light in water?

A 4 x 108ms-1
B 2.25 x 108ms-1
C \(\frac{4}{9}\) x 108ms-1
D 2.25 x 102ms-1
E 4.33 x 108ms-1