Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

Advertisement

Advertisement

61.

When a force F is applied on a wire oflength L and radius r, extension produce is l. If same force F is applied on the same material wire of length 2 L and radius 2r, then extension will be

l

2l

l/2

4l

62.

Energy stored in the unit volume of a wire due to its elasticity is

$\frac{1}{2}(\mathrm{force}\times \mathrm{strain})$

$\frac{1}{2}\mathrm{stress}\times \mathrm{strain}$

stress/strain

force/strain

64.

Copper has face centred cubic (fcc) lattice with interatomic spacing equals to 2.54 $\stackrel{\circ}{\mathrm{A}}$. The value of lattice constant for this lattice is

3.59 $\stackrel{\circ}{\mathrm{A}}$

2.54 $\stackrel{\circ}{\mathrm{A}}$

1.27 $\stackrel{\circ}{\mathrm{A}}$

5.08 $\stackrel{\circ}{\mathrm{A}}$

Advertisement

65.

A copper wire and a steel wire of the same diameter and length are connected end to end and a force is applied which stretches their combined length by 1 cm. Then the two wires will have

the same stress and strain

the same stress but different strain

the same strain but different stress

different stress and strain

66.

A solid sphere of radius r made of a material of bulk modulus K is surrounded by a liquid in cyliridrical container. The massless piston of area A floats on the surface of the liquid. If a mass m is placed on a piston to compress the liquid, then the fractional change in the radius of the sphere will be

$\frac{\mathrm{mg}}{\mathrm{AK}}$

$\frac{2\mathrm{mg}}{\mathrm{AK}}$

$\frac{3\mathrm{mg}}{\mathrm{AK}}$

$\frac{\mathrm{mg}}{3\mathrm{AK}}$

67.

Two wires of same material and length are stretched by the same force. Their masses are in the ratio 4 : 3. The ratio of their elongation will be

16 : 9

9 : 16

4 : 3

3 : 4

68.

A wire suspended vertically from one of its ends is stretched by attaching a weight 100 N to the lower end. The wire stretches by 1mm. The elastic energy stored in the wire is

0.02 J

0.05 J

0.1 J

0.2 J

Advertisement

69.

A circular metal plate of radius 5 cm rests on a layer of centre oil 2mm thick whose coefficient of viscosity is 15.5 dyne cm^{-2} s. The value of shearing stress when a horizontal force move the plate with a speed of 5 cm/s will be

387.5 dyne cm

^{-2}328 dyne cm

^{-2}250 dyne cm

^{-2}428 dyne cm

^{-2}

70.

A steel wire of length 15 m has density = 7.7 × 10^{3} kg/m^{3} and Young's modulus = 2.2 × 10^{11} N/m^{2}. It is subjected to a tension which produces an elastic strain of 1%. Its fundamental frequency of vibration must be

256 Hz

178 Hz

170 Hz

200 Hz

Advertisement