Q. No.The coefficient of linear expansion of brass and steel rods are \(\alpha_1\) and \(\alpha_2\). Lengths of brass and steel rods are \(L_1\) and \(L_2\) respectively. If \((L_2-L_1)\) remains the same at all temperatures, which one of the following relations holds good?
1. \(\alpha_1L_2^2=\alpha_2L_1^2\)
2. \(\alpha_1^2L_2=\alpha_2^2L_1\)
3. \(\alpha_1L_1=\alpha_2L_2\)
4. \(\alpha_1L_2=\alpha_2L_1\)
1. \(\alpha_1L_2^2=\alpha_2L_1^2\)
2. \(\alpha_1^2L_2=\alpha_2^2L_1\)
3. \(\alpha_1L_1=\alpha_2L_2\)
4. \(\alpha_1L_2=\alpha_2L_1\)
1. \( \mathrm{U}_3 =0 \)
2. \(\mathrm{U}_1 >\mathrm{U}_2 \)
3. \(\mathrm{U}_2 >\mathrm{U}_1 \)
4. \(\mathrm{U}_1 =0\)
[Latent heat of ice is \(3.4 \times 10^5~\text{J/kg}\) and \(g=10~\text{N/kg}\)]
1. \(544~\text{km}\)
2. \(136~\text{km}\)
3. \(68~\text{km}\)
4. \(34~\text{km}\)
The value of the coefficient of volume expansion of glycerine is \(5\times10^{-4} \mathrm{~K^{-1}}\). The fractional change in the density of glycerine for a rise of \(40^\circ \text{C}\) in its temperature is:
1. \(0.015\)
2. \(0.020\)
3. \(0.025\)
4. \(0.010\)
On observing light from three different stars \(P\), \(Q\), and \(R\), it was found that the intensity of the violet colour is maximum in the spectrum of \(P\), the intensity of the green colour is maximum in the spectrum of \(R\) and the intensity of the red colour is maximum in the spectrum of \(Q\). If \(T_P\), \(T_Q\), and \(T_R\) are the respective absolute temperatures of \(P\), \(Q\), and \(R\), then it can be concluded from the above observations that:
1. \(T_P>T_Q>T_R\)
2. \(T_P>T_R>T_Q\)
3. \(T_P<T_R<T_Q\)
4. \(T_P<T_Q<T_R\)
The two ends of a metal rod are maintained at temperatures \(100~^\circ\text{C}\) and \(110~^\circ\text{C}.\) The rate of heat flow in the rod is found to be \(4.0\) J/s. If the ends are maintained at temperatures \(200~^\circ \text{C}\) and \(210 ~^\circ \text{C},\) the rate of heat flow will be:
1. \(44.0\) J/s
2. \(16.8\) J/s
3. \(8.0\) J/s
4. \(4.0\) J/s
Liquid oxygen at \(50\) K is heated up to \(300\) K at a constant pressure of \(1\) atm. The rate of heating is constant. Which one of the following graphs represents the variation of temperature with time?
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2. |  |
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4. |  |
1. the entire chamber of the refrigerator is cooled quickly due to convection
2. the motor is not heated
3. the heat gained from the environment is high
4. the heat gained from the environment is low
Assertion: It is hotter over the top of a fire than at the same distance of the side.
Reason: Air surrounding the fire conducts, more heat upward.
- If both the assertion and the reason are true and the reason is a correct explanation of the assertion
- If both the assertion and reason are true but the reason is not a correct explanation of the assertion
- If the assertion is true but the reason is false
- If both the assertion and reason are false
In a new temperature scale, freezing point of water is given a value and boiling point of water is . Reading of new temperature scale for a temperature equal to is
1.
2.
3.
4.
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