If an average person jogs, he produces \(14.5 \times10^3\) cal/min. This is removed by the evaporation of sweat. The amount of sweat evaporated per minute (assuming \(1\) kg requires \(580 \times10^3\) cal for evaporation) is:
1. \(0.25\) kg
2. \(0.50\) kg
3. \(0.025\) kg
4. \(0.20\) kg
Three copper blocks of masses kg respectively are brought into thermal contact till they reach equilibrium. Before contact, they were at . Assuming there is no heat loss to the surroundings, the equilibrium temperature \(T\) is: (\(s\) is the specific heat of copper)
1.
2.
3.
4.
An ideal gas undergoes an isothermal process from some initial state i to
the final state .
(a) dU = 0
(b) dQ = 0
(c) dQ = dU
(d) dQ = dW
Choose the correct alternatives:
1. (a, b, c)
2. (a, d)
3. (b, c, d)
4. (a, c, d)
Consider a cycle followed by an engine (figure).
1 to 2 is isothermal,
2 to 3 is adiabatic,
3 to 1 is adiabatic.
Such a process does not exist, because:
a. | heat is completely converted to mechanical energy in such a process, which is not possible. |
b. | In this process, mechanical energy is completely converted to heat, which is not possible. |
c. | curves representing two adiabatic processes don’t intersect. |
d. | curves representing an adiabatic process and an isothermal process don't intersect. |
Choose the correct alternatives:
1. (a, b)
2. (a, c)
3. (b, c)
4. (c, d)