Assertion (A): | The stretching of a spring is determined by the shear modulus of the material of the spring. |
Reason (R): | A coil spring of copper has more tensile strength than a steel spring of the same dimensions. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is False but (R) is True. |
4. | (A) is True but (R) is False. |
1. | larger in the rod with a larger Young's modulus |
2. | larger in the rod with a smaller Young's modulus |
3. | equal in both the rods |
4. | negative in the rod with a smaller Young's modulus |
1. | (stress)2 × strain | 2. | stress × strain |
3. | \(\dfrac12\) × stress × strain | 4. | stress × (strain)2 |
1. |
2. |
3. |
4. |
1. | tensile, \(F \over 3A\) |
2. | compressive, \(F \over 3A\) |
3. | tensile, \(2F \over 3A\) |
4. | compressive, \(2F \over 3A\) |
1. | \(10^{11}\) | 2. | \(10^{17}\) |
3. | \(10^{7}\) | 4. | \(10^{5}\) |
A wire of cross-section \(A_{1}\) and length \(l_1\) breaks when it is under tension \(T_{1};\) a second wire made of the same material but of cross-section \(A_{2}\) and length \(l_2\) breaks under tension \(T_{2}.\) A third wire of the same material having cross-section \(A,\) length \(l\) breaks under tension \(\dfrac{T_1+T_2}{2}\). Then,
1. | \(A=\dfrac{A_1+A_2}{2},~l=\dfrac{l_1+l_2}{2}\) |
2. | \(l=\dfrac{l_1+l_2}{2}\) |
3. | \(A=\dfrac{A_1+A_2}{2}\) |
4. | \(A=\dfrac{A_1T_1+A_2T_2}{2(T_1+T_2)},~l=\dfrac{l_1T_1+l_2T_2}{2(T_1+T_2)}\) |
When a metal wire elongates by hanging a load on it, the gravitational potential energy is decreased.
1. | this energy completely appears as the increased kinetic energy of the block |
2. | this energy completely appears as the increased elastic potential energy of the wire |
3. | this energy completely appears as heat |
4. | none of these |