Young's Modulus of Elasticity

Q. To break a wire, a force of ${10}^6\frac{N}{m^2}$ is required. If the density of the material is $3\times {10}^{3}kg/m^3,$ then the length of the wire which will break by its own weight will be

1. 34 m
2. 30 m
3. 300 m
4. 3 m

Q.

A uniform steel wire of length 4 m and area of cross-section $3\times {10}^{-6}{m}^2$ is extended by 1 mm by the application of a force. If Young's modulus of steel is $2\times {10}^{11}N{m}^{-2}$, the energy stored in the wire is

1. 0.100 J

2. 0.025 J

3. 0.075 J

4. 0.050 J

Q.

Two wires A and B of same length and of the same material have the respective radii $r_{1}and{r}_2$. Their one end is fixed with a rigid support, and at the other ends equal twisting couple is applied. Then the ratio of the angle of twist at the end of A and The angle of twist at the end of B will be

1. 

2. 

3. 

4. 

Q. The Young’s modulus of three materials are in the ratio 2:2:1. Three wires made of these materials have their cross-sectional areas in the ratio 1:2:3. For a given stretching force the elongation's in the three wires are in the ratio

1. 1:2:3
2. 3:2:1
3. 5:4:3
4. 6:3:4

Q. A uniform slender rod of length L, cross sectional area A and Young’s modulus Y is acted upon by the forces shown in the figure. The elongation of the rod is

1. 
2. 
3. 
4. 

Q.

A 5 metre long wire is fixed to the ceiling. A weight of 10 kg is hung at the lower end and is 1 metre above the floor. The wire was elongated by 1 mm. The energy stored in the wire due to stretching is

1. Zero

2. 0.05 joule

3. 100 joule

4. 500 joule

Q. One end of a long metallic wire of length L, area of cross-section A and Young’s modulus Y is tied to the ceiling. The other end is tied to a massless spring of force constant k. A mass m hangs freely from the free end of the spring. It is slightly pulled down and released. Its time period is given by

1. 
2. 
3. 
4. 

Q. A wire of length L and radius r is rigidly fixed at one end. On stretching the other end of the wire with a force F, the increase in its length is l. If another wire of same material but of length 2L and radius 2r is stretched with a force of 2F, the increase in its length will be

1. 
2. 
3. 
4. 

Q.

Two wires of same diameter of the same material having the length l and 2l. If the force F is applied on each, the ratio of the work done in the two wires will be

1. 1 : 4

2. 2 : 1

3. 1 : 1

4. 1 : 2

Q. Two blocks of masses $m_1$ and $m_2$ are joined by a wire of Young’s modulus Y via a massless pulley. The area of cross-section of the wire is S and its length is L. When the system is released, increase in length of the wire is

1. 
2. 
3. 
4.