(a) | The mass \(m\) should be suspended close to wire \(A\) to have equal stresses in both wires. |
(b) | The mass \(m\) should be suspended close to \(B\) to have equal stresses in both wires. |
(c) | The mass \(m\) should be suspended in the middle of the wires to have equal stresses in both wires. |
(d) | The mass \(m\) should be suspended close to wire \(A\) to have equal strain in both wires. |
1. | (b), (c) | 3. | (b), (d) |
2. | (a), (d) | 4. | (c), (d) |
1. | Both the rods will elongate but there shall be no perceptible change in shape. |
2. | The steel rod will elongate and change shape but the rubber rod will only elongate. |
3. | The steel rod will elongate without any perceptible change in shape but the rubber rod will elongate and the shape of the bottom edge will change to an ellipse. |
4. | The steel rod will elongate without any perceptible change in shape but the rubber rod will elongate with the shape of the bottom edge tapered to a tip at the centre. |
The temperature of the wire is doubled. Young's modulus of elasticity:
1. | will also double. | 2. | will become four times. |
3. | will remain the same. | 4. | will decrease. |
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. |
The Marina trench is located in the Pacific Ocean, and at one place it is nearly \(11 \) km beneath the surface of the water. The water pressure at the bottom of the trench is about \(1.1 \times10^8\) Pa. A steel ball of initial volume \(0.32\) m3 is dropped into the ocean and falls to the bottom of the trench. What is the change in the volume of the ball when it reaches the bottom? (Given: \(B_{\mathrm{steel}}=1.6 \times10^{11}\) N/m2)
1. | \(1.01\times10^{-3}\) m3 | 2. | \(2.2 \times10^{-4}\) m3 |
3. | \(1.9 \times10^{-3}\) m3 | 4. | none of these |