Physics Past Questions and Answers

A converging lens has a focal length of 5cm. Determine its power

A +20.0
B +0.2
C -20.00
D -0.2

Question 912:

Which of the following pairs of rays shows the widest separation in the spectrum of white light?

A Green and blue
B Orange and indigo
C Blue and violet
D Red and yellow

Question 913:

Which of the following statements about the human eye and the camera is correct?

A Both form virtual image of objects
B The image formed by the eye is upright in the retina while that formed by the camera is inverted on the film
C The inside of both of them is blackened to absorb unwanted light
D The focal length of both eye lens and the camera lens can be varied

Question 914:

The speed of sound in air is is directly proportional to

A Its temperature on the celsius scale
B Ite temperature in the thermodynamic scale
C The cube root of its temperature on its celcius csale
D The square roor of its temperature on the absolute scale

Question 915:

A sonometer wire of linear density 0.08kg m^-1 subjected to a tension of 800N is plucked. Calculate the speed of a pulse which moves from one end of the wire to the other

A 179.0ms^-1
B 100.0ms^-1
C 15.8ms^-1
D 8.0ms^-1