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. |
Consider two cylindrical rods of identical dimensions, one of rubber and the other of steel. Both the rods are fixed rigidly at one end of the roof. A mass M is attached to each of the free ends at the centre of the rods.
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. |
A rod of length \(l\) and negligible mass is suspended at its two ends by two wires of steel (wire \(A\)) and aluminium (wire \(B\)) of equal lengths (figure). The crosse-sectional areas of wires \(A\) and \(B\) are \(1.0~\text{mm}^2\) and \(2.0~\text{mm}^2\) respectively. \((Y_{\text{Al}}=70\times10^9~\text{N/m}^2\) and \(Y_{\text{steel}}=200\times10^9~\text{N/m}^2)\)
(a) | Mass \(m\) should be suspended close to wire \(A\) to have equal stresses in both wires. |
(b) | Mass \(m\) should be suspended close to \(B\) to have equal stresses in both wires. |
(c) | Mass \(m\) should be suspended in the middle of the wires to have equal stresses in both wires. |
(d) | Mass \(m\) should be suspended close to wire \(A\) to have equal strain in both wires. |
The correct statements are:
1. (b, c)
2. (a, d)
3. (b, d)
4. (c, d)