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 \(100 N\) hangs froma steel wire of length 3 \(m\) and cross-sectional area \(1.5 \times 10-6 m 2\). Calculate the extension is \(0.25 mm\), calculate the extension produced

A. \(1 mm\)
B. \(1.5 mm\)
C. \(0.1 mm\)
D. \(0.15 mm\)

Question 4709:

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

A. \(18 N / m ^{2}\)
B. \(1800 N / m 2\)
C. \(180 N / m _{2}\)
D. \(1.8 \times 1011 N / m 2\)

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