Physics Past Questions and Answers

A piece of cloth appears green in sunlight. When held in red light, it will appear

A Green
B Blue
C Red
D Black

Question 807:

Dispersion of white light by a glass prism occurs because

A White light consist of a mixture of seven different colour
B The refractive index of glass is different from each constituent colour of white light
C The speed of each colour of light in the glass is proportional to the refractive index of glass for each colour
D The speed of each colour of light in the glass is proportional to the angle of refraction in he prism

Question 808:

Which of the following statements about sound is correct?

A When sound travels from air to a denser medium, it is refracted away from the normal at the point of incidence
B Sound travels faster in air than in water
C The wavelength of sound changes when it travels from to water
D The frequency of it travels from air to water

Question 809:

The diagram above shows the wire of a sonometer box set into resonance by a vibrating tuning fork of frequency f, when the wire is stretched by a tension T, the resonating length of the wire is I while the wavelength of the sound produced is \(\lambda\). Which of the following statements is not correct? The wave produced on the wire is

A Stationary and lonitudinal
B Stationary and mechanical
C Mechanical and longitudinal
D Progessive and transverse

Question 810:

The diagram above shows the wire of a sonometer box set into resonance by a vibrating tuning fork of frequency f, when the wire is stretched by a tension T, the resonating length of the wire is I while the wavelength of the sound produced is \(\lambda\). Which of the following statements about the frequency of vibration of the wire is not correct?

A Proportional to the mass per unit length of the wire
B Equal to the frequency of the tuning fork
C Inversely proportional to the length of the wire
D Proportional to the sqare root of the tension