The Young's modulus of a wire of length 'L' and radius 'r' is 'Y'. If length is reduced to L/2 and radius r/2, then Young's modulus will be
1. Y/2
2. Y
3. 2Y
4. 4Y
Three wires \(A,B,C\) made of the same material and radius have different lengths. The graphs in the figure show the elongation-load variation. The longest wire is:
1. \(A\)
2. \(B\)
3. \(C\)
4. All of the above
The breaking stress of a wire depends upon:
1. | material of the wire. |
2. | length of the wire. |
3. | radius of the wire. |
4. | shape of the cross-section. |
If Young modulus (Y) equal to bulk modulus (B). Then the Poisson ratio is :
1.
2.
3.
4.
A constrained steel rod of length \(l\), area of cross-section \(A\), Young's modulus \(Y\) and coefficient of linear expansion \(\alpha\) is heated through \(t^{\circ}\text{C}\). The work that can be performed by the rod when heated is:
1. \((YA\alpha t)(l\alpha t)\)
2. \(\frac{1}{2}(YA\alpha t)(l\alpha t)\)
3. \(\frac{1}{2}(YA\alpha t)\frac{1}{2}(l\alpha t)\)
4. \(2(YA\alpha t)(l\alpha t)\)
A gas undergoes a process in which its pressure P and volume V are related as . The bulk modulus for the gas in the process is:
[This question includes concepts from Kinetic Theory chapter]
1.
2.
3. nP
4.
The bulk modulus of a spherical object is \(B\). If it is subjected to uniform pressure \(P\), the fractional decrease in radius will be:
1. \(\frac{P}{B}\)
2. \(\frac{B}{3P}\)
3. \(\frac{3P}{B}\)
4. \(\frac{P}{3B}\)
1. | \(1:2\) | 2. | \(2:1\) |
3. | \(4:1\) | 4. | \(1:1\) |
Copper of fixed volume V is drawn into a wire of length l. When this wire is subjected to a constant force F, the extension produced in the wire is Δl. Which of the following graphs is a straight line?
(1) Δl versues 1/l
(2) Δl versus l2
(3) Δl versus 1/l2
(4) Δl versus l
The following four wires are made of the same material. Which of them will have the largest extension when the same tension is applied?
(1) Length=50 cm, diameter=0.5 mm
(2) Length=100 cm, diameter=1 mm
(3) Length=200 cm, diameter=2 mm
(4) Length=300 cm, diameter=3 mm