Physics Past Questions and Answers

When a sound wave passes from air into water its

A Speed and frequency increases but its wavelength remains the same
B Speed and wavelength increases but its frequency remains the same
C Speed decreases
D Speed increases but its frequency and wavelength decreases

Question 4102:

A convex mirror is used as a driving mirror because
I. its image is erect
II. It has a large field of view
III. It has a long focal length
Identify the CORRECT statement(s)

A I and III only
B I and II only
C II and IIII only
D I, II and III only

Question 4103:

Two mirrors of the same length are arranges as show in the diagram. A ray of light NO strikes the system at O and emerges along PQ. The emergent ray has been deviated through

A 220\(^o\)
B 200\(^o\)
C 210\(^o\)
D 180\(^o\)

Question 4104:

A magnetic needle is suspended first at the earth's north magnetic pole and then at a point on the magnetic equator. The respective angles between the needle and the horizontal are

A 0\(^o\) and 0\(^o\)
B 60\(^o\) and 60\(^o\)
C 90\(^o\) and 90\(^o\)
D 90\(^o\) and 0\(^o\)

Question 4105:

A hydrometer is an instrument for measuring the

A A depth of water of water in a vessel
B Relative density of a liquid by the method of flotation
C Relative density of a liquid by finding the apparent loss in weight
D Relative humidity of the air