The value of the coefficient of volume expansion of glycerin is $$5\times10^{-4}$$ K-1. The fractional change in the density of glycerin for a temperature increase of $$40^\circ \mathrm{C}$$ will be:

 1 $$0.015$$ 2 $$0.020$$ 3 $$0.025$$ 4 $$0.010$$
Subtopic:  Thermal Expansion |
82%
From NCERT
NEET - 2015
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The coefficients of linear expansion of brass and steel rods are α1 and α2, lengths of brass and steel rods are l1 and l2 respectively. If (l2 - l1) is maintained the same at all temperatures, Which one of the following relations holds good?

1. α1l22 = α2l12

2. α12l= α22l1

3. α1l= α2l2

4. α1l= α2l1

Subtopic:  Thermal Expansion |
83%
From NCERT
NEET - 2016
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A copper rod of $$88$$ cm and an aluminium rod of an unknown length have an equal increase in their lengths independent of an increase in temperature. The length of the aluminium rod is:
$$\left(\alpha_{Cu}= 1.7\times10^{-5}~\text{K}^{-1}~\text{and}~\alpha_{Al}= 2.2\times10^{-5}~\text{K}^{-1}\right)$$
1. $$68~\text{cm}$$
2. $$6.8~\text{cm}$$
3. $$113.9~\text{cm}$$
4. $$88~\text{cm}$$

Subtopic:  Thermal Expansion |
76%
From NCERT
NEET - 2019
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A pendulum clock runs faster by 5 seconds per day at $$20^{\circ}\mathrm {C}$$ and goes slow by 10 second per day at $$35^{\circ}\mathrm {C}$$. It shows the correct time at a temperature of:
1. $$27.5^{\circ}\mathrm {C}$$
2. $$25^{\circ}\mathrm {C}$$
3. $$30^{\circ}\mathrm {C}$$
4. $$33^{\circ}\mathrm {C}$$

Subtopic:  Thermal Expansion |
65%
From NCERT
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Two rods, one made of aluminium and the other made of steel, having initial lengths $$l_1$$ and $$l_2$$ are connected together to form a single rod of length ${l}_{1}+{l}_{2}$. The coefficient of linear expansion for aluminium and steel are ${\alpha }_{a}$ and ${\alpha }_{s}$ respectively. If the length of each rod increases by the same amount when their temperature is raised by $$t^\circ \mathrm{C},$$ then the ratio $$\frac{l_1}{l_1+l_2}$$ is:
1. $\frac{{\alpha }_{s}}{{\alpha }_{a}}$

2. $\frac{{\alpha }_{a}}{{\alpha }_{s}}$

3. $\frac{{\alpha }_{a}}{{\alpha }_{a}+{\alpha }_{s}}$

4. $\frac{{\alpha }_{s}}{{\alpha }_{a}+{\alpha }_{s}}$

Subtopic:  Thermal Expansion |
59%
From NCERT
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The diagram shows a bimetallic strip used as a thermostat in a circuit. Copper expands more than Invar for the same temperature rise.

What will be switched on when the bimetallic strip becomes hot?

 1 bell only 2 lamp and bell only 3 motor and bell only 4 lamp, bell, and motor

Subtopic:  Thermal Expansion |
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