Carnot Cycle

Q. The temperature inside and outside a refrigerator are 273K and 300K respectively .Assuming that the refrigerator cycle is reversible for every joule of workdone the heat delivered to the surrounding is.

Q.

The temperature of reservoir of Carnot's engine operating with an efficiency of 70% is 1000K. The temperature of its sink is

1. 300 K

2. 500 K

3. 700 K

4. 400 K

Q.

A motor boat is travelling with a speed of 3.0 m/sec. If the force on it due to water flow is 500 N, the power of the boat is

1. 150 kW

2. 15 kW

3. 1.5 kW

4. 150 W

Q. A lead ball moving with velocity v strikes a wall and stops. If 50% of its energy is converted into heat, then what will be the increase in temperature. ( specific heat of lead is s

Q. how newtons law can be used to find specific heat of liquids in laboratory ?

Q. If change in internal energy is -80J.The work done by sysyem is +40 J.Calculare the heat change.

Q. A refrigerator is to maintain eatables kept inside at 90C. If room temperature is 360C, calculate the coefficient of performance

Q.

The temperature inside a refrigerator is 4^oC and the room temperature is 27^oC. How many joules of heat will be delivered to the room for each joule of electricity consumed by the refrigerator?( Treat the refrigerator as ideal).

1. 1 J

2. 12 J

3. 13 J

4. 8.3 J

Q. For an ideal gas R=2÷3Cv in adiabatic process the pressure of the gas proportional to

Q. 14. Calculate the change in internal energy of the system when it absorbs 20 kJ of heat from the surrounding and does work equivalent to 50 kJ.

Q. the amount of heat energy required to raise the temperature of 1g of He at NTP from T1 K to T2 K is ?

Q. The maximum efficiency of a heat engine operating between ${100}^{\circ }C$ and ${25}^{\circ }C$ is:

1. 22.2%
2. 25%
3. None of the above
4. 20%

Q. When the amount of work done is 333 Cal and the change in internal energy is 167 cal what is the amount of heat supplied ?

Q. What is the differebce between Carnot engine and Carnot cycle

Q. A reversible engine converts one-sixth of the heat input into work. When the temperature of the sink is reduced by ${62}^{\circ }C$, the efficiency of the engine is doubled. The temperatures of the source and sink are

1. ${80}^{\circ }C,{37}^{\circ }C$
2. ${95}^{\circ }C,{28}^{\circ }C$
3. ${90}^{\circ }C,{37}^{\circ }C$
4. ${99}^{\circ }C,{37}^{\circ }C$

Q. 70.What is meant by isothermal elasticity?

Q. Q 72/200 For the reaction, A(s)2B(g)+ C(g) At equilibrium total pressure is 1.5atm at a constant temperature T(K). Kp of thereaction at T(K) is

Q. A Carnot engine absorbs $Q_1$ amount of heat from a reservoir at an absolute temperature $T$ and rejects heat to a sink at a temperature of $T/3$. The amount of heat rejected is

1. $Q_1/4$
2. $Q_1/3$
3. $Q_1/2$
4. $2Q_1/3$

Q.

In one complete cycle, a heat engine extracts heat $Q_h$ from a thermal reservoir, does work W and does not eject any heat into the environment. This heat engine is impossible because its operation violates:

1. Conservation of energy ($1^{st}$ Law) only
2. $2^{nd}$ Law only
3. Both $1^{st}$ Law and $2^{nd}$ Law
4. Neither $1^{st}$ nor $2^{nd}$ law

Q. isothermal process?

Q. what are the differences between cyclic and non cyclic processes?

Q.

Three samples A, B and C of same gas initially having same volume and pressure are expanded to double their initial volume. One sample A is expanded isothermally, B is expanded adiabatically and C is expanded isobarically. In which case is the work done minimum?

1. In adiabatic expansion

2. Work done in all cases is same

3. In isothermal expansion

4. In isochoric expansion

Q. A refrigerator uses 400 J of work to remove 200 J of heat from its contents. How much heat must it reject to its surroundings?

1. 400 J
2. 200 J
3. 600 J
4. 800 J

Q. The temperature inside and outside of the refrigerator is $260\text{K}$ and $315\text{K}$ respectively. Assuming that the refrigerator cycle is reversible, calculate the heat delivered to the surroundings for every joule of work done.

1. $5\text{J}$
2. $6.19\text{J}$
3. $5\text{J}$
4. $5.73\text{J}$

Q. The efficiency of carnot engine is $50\%$ and temperature of sink is $500\text{K}$. If temperature of source is kept constant and its efficiency raised to $60\%$, then required temperature of the sink will be:

1. $100\text{K}$
2. $600\text{K}$
3. $400\text{K}$
4. $500\text{K}$

Q. A window air conditioner is brought into the center of a dorm room and turned on. After several minutes, the temperature of the room:

1. increases
2. decreases
3. remains constant
4. depends on the brand of the AC

Q. The source of a Carnot engine is at $500K$ but sink is at $300K$. The efficiency of engine will be:

1. $0.3$
2. $0.2$
3. $0.6$
4. $0.4$

Q. $$\begin{gathered} Anidealgasundergoestheprocess1\to 2asshowninthefigure,theheatsuppliedandworkdoneintheprocessis∆Qand∆Wrespectively.Theratio∆Q:∆Wis \\ \left(1\right)\gamma :\gamma -1 \\ \left(2\right)\gamma \\ \left(3\right)\gamma -1 \\ \left(4\right)\gamma -1:\gamma \end{gathered}$$

Q.

What is the efficiency of a Carnot engine operating between higher temperature $T_H$ and lower temperature $T_L$?

1. $T_H-T_L$

2. $\frac{T_H-T_L}{T_L}$

3. $\frac{T_H-T_L}{T_H}$

4. $\frac{T_L-T_H}{T_L}$

Q. what is carnot cycle. does its efficiency depend on working substance?