A metal string \(A\) is suspended from a rigid support and its free end is attached to a block of mass \(M.\) Second block having mass \(2~M\) is suspended at the bottom of the first block using a string \(B\). The area of cross sections of strings \(A\) and \(B\) are same. The ratio of lengths of strings of \(A\) to \(B\) is \(2\) and the ratio of their Young's moduli \(Y_A/Y_B\) is \(0.5.\) The ratio of elongations in \(A\) to \(B\) is:
1. \(1\)
2. \(4\)
3. \(8\)
4. \(6\)
Subtopic:  Young's modulus |
 79%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.

Figure represents the extension \((\Delta{l})\) of a wire of length \(1\) meter, suspended from the ceiling of the room at one end with a load \(W\) connected to the other end. If the cross-sectional area of the wire is \(10^{-5}~ \text{m}^{2}\) then the Young's modulus of the wire is: (in \(\text{N/m}^2\)
        
1. \(1.0 \times 10^{11}\)
2. \(2.0 \times 10^{10} \)
3. \(1.0 \times 10^{10} \)
4. \(2.0 \times 10^{11}\)
Subtopic:  Young's modulus |
Level 4: Below 35%
Please attempt this question first.
Hints
Please attempt this question first.

The two wires \(A\) and \(B\) of equal cross-section but of different materials are joined together. The ratio of Young's modulus of wire \(A\) and wire \(B\) is \(20/11\). When the joined wire is kept under certain tension the elongation in the wires \(A\) and \(B\) are equal. If the length of wire \(A\) is \(2.2~\text{m},\) then the length of wire \(B\) is: (in m)
1. \(1.1\)
2. \(2.22\)
3. \(1.21\)
4. \(4.44\)
Subtopic:  Young's modulus |
 86%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.

advertisementadvertisement

The diameter of a wire measured by a screw gauge of least count \(0.001\) cm is \(0.08\) cm. The length measured by a scale of least count \(0.1\) cm is \(150\) cm. When a weight of \(100~\text{N}\) is applied to the wire, the extension in length is \(0.5\) cm, measured by a micrometer of least count \(0.001\) cm. The error in the measured Young's modulus is \(\alpha \times 10^{9} ~\text{N/m}^2 \). The value of \(a\) is:
(Ignore the contribution of the load to Young's modulus error calculation)
1. \(1.3\)
2. \(1.65\)
3. \(0.13\)
4. \(0.25\)
Subtopic:  Young's modulus |
 69%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.

The Young's modulus of steel wire of radius \(r\) and length \( L\) is \(Y\). If the radius \(r\) and length \(L\) of the wire are doubled then the value of \(Y\).
1. increases by two times
2. reduces by half
3. remains unchanged
4. becomes one fourth
Subtopic:  Young's modulus |
 93%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.

A string \(A\) of length \(0.314~\text{m}\) and Young's modulus \(2\times 10^{10}~\text{N/m}^2\) is connected to another string \(B\) of length and Young's modulus both twice of those of \(A\). This series combination of strings is then suspended from a rigid support and its free end is fixed to a load of mass \(0.8~\text{kg}\). The net change in length of the combination is: (in mm)
(radius of both the strings is \(0.2~\text{mm}\) and acceleration due to gravity \(=10~\text{m/s}^2\)) (Mass of both strings is to be neglected as compared to the mass of load)
1. \(3\)
2. \(2\)
3. \(1.9\)
4. \(1\)
Subtopic:  Young's modulus |
 75%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.

advertisementadvertisement

Two wires \(A\) and \(B \) made of different materials of length \(6.0~\text{cm}\) and \(5.4~\text{cm}\), respectively and area of cross sections \(3.0 \times10^{-5} ~\text{m}^2 \) and \(4.5 \times10^{-5} ~\text{m}^2 \) respectively are stretched by the same magnitude under a given load. The ratio of the Young's modulus of \(A\) to that \(B\)  is \(x:3.\) The value \(x\) is:
1. \(1\)  
2. \(4\)
3. \(2\)
4. \(5\)
Subtopic:  Young's modulus |
 85%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.

A \(3~\text{m}\) long wire of radius \(3~\text{mm} \) shows an extension of \(0.1~\text{mm} \) when loaded vertically by a mass of \(50~\text{kg} \) in an experiment to determine Young's modulus. The value of Young's modulus of the wire as per this experiment is \(P × 10^{11}~\text{Nm}^{-2} , \) where the value of \(P \) is:
(Take \(g=3π~ \text{m/s}^2\))
1. \(5\)
2. \(10 \)
3. \(25\)
4. \(2.5\)
Subtopic:  Young's modulus |
 92%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.

Two wires \(A\) and \(B \) are made of same material having ratio of lengths \(\dfrac {L_A}{L_B} = \dfrac{1}{3} \) and their diameters ratio \(\dfrac{d_A}{d_B} = 2.\) If both the wires are stretched using same force, what would be the ratio of their respective elongations.
1. \(1:12\)
2. \(3:4\)
3. \(1:6\)
4. \(1:3\)
Subtopic:  Young's modulus |
 77%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.

advertisementadvertisement

A steel wire of length \(2 \text{ m}\) and Young's modulus \(2.0 \times 10^{11} ~\text{Nm}^{-2}\) is stretched by a force. If Poisson ratio and transverse strain for the wire are \(0.2\) and \(10^{-3}\) respectively, then the elastic potential energy density of the wire is: (in \(\times10^5 \))(in \(SI\) units). 
1. \(25 \times 10^2 \)
2. \(25 \times 10^3 \)
3. \(25 \times 10^5 \)
4. \(25 \times 10^4 \)
Subtopic:  Young's modulus |
 73%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.