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. $\frac{1}{3}$

2. $\frac{2}{3}$

3. $\frac{1}{2}$

4. $\frac{1}{4}$

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. $2(YA\alpha t)(l\alpha t)$

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 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

A gas undergoes a process in which its pressure P and volume V are related as ${\mathrm{VP}}^{\mathrm{n}}=\mathrm{constant}$. The bulk modulus for the gas in the process is:

[This question includes concepts from Kinetic Theory chapter]

1. $\frac{P}{n}$

2. $P^{1/n}$

3. nP

4. $P^n$

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. $\frac{P}{3B}$

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