Physics Past Questions and Answers

Question 4706:

The speed of light in air is 3.0x108 m/s. What is its speed in glass having a refractive index of 1.65?

A. 6.0x108 m/s
B. 4.95 x108 m/s
C. 1.82 x108 m/s
D. 1.65 x108 m/s

Question 4707:

Atmospheric pressure is 1.0x105 N/m2. If the barometer liquid has a density of 1250 kg/m³.
what is the minimum length of the tube required? g=10m/s2.

A. 7.8m
B. 0.76m
C. 8.0m
D. 10 m

Question 4708:

Young's modulus for steel is 2x1011 N/m2. Aweight of $100N$ hangs froma steel wire of length 3 $m$ and cross-sectional area $1.5\times 10-6m2$. Calculate the extension is $0.25mm$, calculate the extension produced

A. $1mm$
B. $1.5mm$
C. $0.1mm$
D. $0.15mm$

Question 4709:

A load of $50N$ is attached to one end of a long vertical wire of length $4m$ and diameter $2.4mm$ whose other end is fixed If the extension is $0.25$ $mm$. calculate the Young modulus of the material of the wire.

A. $18N/m^2$
B. $1800N/m2$
C. $180N/m_2$
D. $1.8\times 1011N/m2$

Question 4710:

Which of the following statements is not true about friction force is not correct.

A. The centre of gravity of a body isthe point where the resultant force of attmction or weight of the body acts
B. The lower the centre of gravity of a body the morestable thebody is
C. The higher the centre of gravity of a body the morestable the body is
D. It is the point at which the weight of the body appears to be acting