Identify the incorrect statement. from Physics Mechanical Proper

Previous Year Papers

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

Test Series

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

Test Yourself

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

 Multiple Choice QuestionsMultiple Choice Questions

21.

A steel plate of size 6 cm x 6 cm is to be coated by a metal on both sides with a coating thickness of 0.1 mm by electrolysis. If the density and ece of the metal are respectively 10 g cm-3 and 0.001 gC-1 then the strength of the current to complete the process in one hour is

  • 1 A

  • 0.5 A

  • 6 A

  • 2 A


22.

Choose the wrong statement

  • The bulk modulus for solids is much larger than for liquids

  • Gases are least compressible

  • The incompressibility of the solids is due to the tight coupling between neighbouring atoms

  • The reciprocal of the bulk modulus is called compressibility


Advertisement

23.

Identify the incorrect statement.

  • Young's modulus and shear modulus are relevant only for solids.

  • Bulk modulus is relevant for solids, liquids and gases.

  • Alloys have larger values of Young's modulus than metals.

  • Metals have larger values of Young's modulus than elastomers


C.

Alloys have larger values of Young's modulus than metals.

Because the alloys having high densities ie, alloys have larger values of Young's modulus than metals.


Advertisement
24.

A lead bullet strikes against a steel plate with a velocity 200 ms-1. If the impact is perfectly inelastic and the heat produced is equally shared between the bullet and the target, then the rise in temperature of the bullet is (Specific heat capacity of lead = 125 J Kg-1 K-1)

  • 80°C

  • 60°C

  • 160°C

  • 40°C


Advertisement
25.

Which one of the following statements is correct? In the case of

  • shearing stress there is change in volume

  • tensile stress there is no change in volume

  • shearing stress there is no change in shape

  • hydraulic stress there is no change in volume


26.

The Young's modulus of the material of a wire is 2 × 1010 Nm-2. If the elongation strain is 1 %, then the energy stored in the wire per unit volume in Jm-3 is

  • 106

  • 108

  • 2 × 106

  • 2 × 108


27.

If the volume of a block of aluminium is decreased by 1%, the pressure (stress) on its surface is increased by (Bulk modulus of Al = 7.5 1010 Nm-2)

  • 7.5 × 1010 Nm-2

  • 7.5 × 108 Nm-2

  • 7.5 × 106 Nm-2

  • 7.5 × 104 Nm-2


28.

The length of a rubber cord is 11 metre when the tension is 4 N and l2 metre when the tension is 6 N. The length when the tension is 9 N, is

  • (2.5 l2 − 1.5 l1) m

  • (6 l2 − 1.5 l1) m

  • (3 l2 − 2 l1) m

  • (3.5 l2 − 2.5 l1) m


Advertisement
29.

A wire of natural length l, Young's modulus Y and area of cross-section A is extended by x. Then the energy stored in the wire is given by

  • 12 YAl x2

  • 13 YAl x2

  • 12 YlA x2

  • 12 YAl2 x2


30.

A piece of solid weighs 120 g in air, 80 g in water and 60 g in a liquid. The relative density of the solid and that of the liquid are respectively

  • 3, 2

  • 2, 34

  • 3, 32

  • 4, 3


Advertisement