Physics Past Questions and Answers

A sound wave of velocity 350 ms^-1 is directed towards the surface of water. lf the ratio of the wavelength of sound in water to that in air is 425:100, calculate the velocity on the wave in water

A 82.4ms^-1
B 148.8ms^-1
C 350.0ms^-1
D 1487.5ms^-1
E 3500.5ms^-1.

Question 512:

The speed of sound in air is 330ms^-1. How far from the centre of a storm is an observer who hears a thunder clap 2s after the lightning flash? (Neglect the time taken by light to travel to the observer)

A 1320m
B 660m
C 600m
D 330m
E 165m

Question 513:

The diagram above illustrates a variation of the displacement y of a wave particle with time t. lf the velocity of wave is 250ms^-1, calculate the distance between two successive particles which are in phase

A 20m
B 2.5m
C 3.0m
D 5.0m
E 50.0m

Question 514:

The diagram above represents a stationary wave set up in a string which is fixed at both ends. lf the frequency of the wave is 256Hz and the distance N1 N2 equals 1.5m, calculate the speed of the wave.

A 128ms^-1
B 192ms^-1
C 384ms^-1
D 768ms^-1
E 1536ms^-1

Question 515:

CalcuIate the power delivered by a 3-phase line if its voltage and current at 132KV and 60A respectively.

A 2.38 x 10⁷W
B 7.92 x 10⁶W
C 3.96 x 10⁶W
D 2.64 x 10⁶W
E 7.92 x 10⁴W