At what temperature do both the Centigrade and Fahrenheit thermometers show the same reading
1. –20
2. –40
3. 42
4. 0
The temperature of substance increases by 27°C this increases is equal to (in kelvin)
1. 300 K
2. 2.46 K
3. 27 K
4. 7 K
In the adjoining figure, various isothermals are shown for a real gas. Then:
1. EF represents liquification
2. CB represents liquification
3. HI represents the critical temperature
4. AB represents gas at a high temperature
The change in volume V with respect to an increase in pressure P has been shown in the figure for a non-ideal gas at four different temperatures and . The critical temperature of the gas is
1.
2.
3.
4.
The temperature of a substance increases by . On the Kelvin scale, this increase is equal to
1. 300 K
2. 2.46 K
3. 27 K
4. 7 K
Two rods \(A\) and \(B\) of different materials are welded together as shown in the figure. Their thermal conductivities are \(K_1\) and \(K_2.\) The thermal conductivity of the composite rod will be:
1. | \(\frac{3(K_1+K_2)}{2}\) | 2. | \(K_1+K_2\) |
3. | \(2(K_1+K_2)\) | 4. | \(\frac{(K_1+K_2)}{2}\) |
The temperature below which gas should be cooled, before it can be liquified by pressure only is termed as :
1. The dew point
2. The freezing point
3. The saturation point
4. The critical point
The vapour of a substance behaves as a gas :
1. Below the critical temperature
2. Above the critical temperature
3. At 100°C
4. At 1000°C
The power radiated by a black body is \(P\) and it radiates maximum energy at wavelength \(\lambda_0\)
1. \( \frac{3}{4} \)
2. \( \frac{4}{3} \)
3. \( \frac{256}{81} \)
4. \( \frac{81}{256}\)
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. \(\alpha_1L_2=\alpha_2L_1\)