A student plots a graph from his readings on the determination of Young modulus of a metal wire but forgets to put the labels (figure). The quantities on X and Y-axes may be respectively,
(a) | weight hung and length increased |
(b) | stress applied and length increased |
(c) | stress applied and strain developed |
(d) | length increased and the weight hung |
Choose the correct option:
1. | (a) and (b) |
2. | (b) and (c) |
3. | (a), (b) and (d) |
4. | all of these |
1. | 2. |
3. | 4. |
Assertion (A): | Soft steel can be made red hot by continued hammering on it, but hard steel cannot. |
Reason (R): | Energy transfer in the case of soft is large as in hard steel. |
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 True but (R) is False. |
4. | (A) is False but (R) is True. |
Assertion (A): | Bulk modulus of elasticity \(B\) represents the incompressibility of the material. |
Reason (R): | \( B=-\frac{\Delta p}{\Delta V / V} \), where symbols have their usual meaning. |
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 True but (R) is False. |
4. | (A) is False but (R) is True. |
Assertion (A): | Young's modulus for a perfectly plastic body is zero. |
Reason (R): | For a perfectly plastic body, restoring force is zero. |
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 True but (R) is False. |
4. | Both (A) and (R) are False. |
Assertion (A): | The bridges are declared unsafe after long use. |
Reason (R): | The bridges lose their elastic strength with time. |
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 True but (R) is False. |
4. | Both (A) and (R) are False. |
Assertion (A): | Identical springs of steel and copper are equally stretched. More work will be done on the steel spring. |
Reason (R): | Steel is more elastic than copper. |
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 True but (R) is False. |
4. | Both (A) and (R) are False. |
Assertion (A): | Lead is more elastic than rubber. |
Reason (R): | If the same load is attached to lead and rubber wires of the same cross-sectional area, the strain of lead is very much less than that of rubber. |
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 true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion(A): | Stress is the restoring force per unit area of a body. |
Reason(R): | Rubber is more elastic than steel. |
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 true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | On elastic bodies, though we apply force and experience elongation, it is a general practice to plot stress versus strain instead of plotting force versus elongation graph. |
Reason (R): | Stress versus strain plotting makes the graph independent of the geometry of the sample body and reflects only the material property. |
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 True but (R) is False. |
4. | Both (A) and (R) are False. |