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A carnot engine takes in 3 xx 10^6 cal o...

A carnot engine takes in `3 xx 10^6` cal of heat from source at `627^@ C` and gives it to a sink at `27^@ C`. The work done by the engine would be _____ (J=4.2 J/cal).

A

zero

B

`4.2xx10^6` J

C

`8.4xx10^6` J

D

`16.8 xx10^6` J

Text Solution

Verified by Experts

The correct Answer is:
C
Temperature of heat source `T_1`=273+627=900 K
Temperature of heat sink `T_2`= 273+27 = 300 K
Heat absorbs from source ,
`Q_1=3xx10^6` cal
`=4.2xx3xx10^6` Joule
`rArr` The efficiency of carnot engine,
`eta=1-T_2/T_1`
`=1-300/900`
`=600/900`
`=2/3`
Now efficiency of carnot engine `eta=W/Q_1`
`therefore W=eta Q_1`
`=2/3xx4.2xx3xx10^6`
`=8.4xx10^6` J
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KUMAR PRAKASHAN-THERMODYANMICS -Section-F Questions from Module
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  3. If a gas is heated at constant pressure, then what percentage of total...

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  4. By which one of the following working temperature the efficiency of a ...

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  5. A carnot engine converts one sixth of the heat input into work. The si...

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  7. The efficiency of carnot engine working between temperatures 200^@ C a...

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  8. A gaseous mixture consists of 16 g of helium (He) and 16 g oxygen (O2)...

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  9. During an adiabatic process the pressure of gas is found to be proport...

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  10. A system is taken along different path in the graph of Pto V from its ...

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  11. A refrigerator is to maintain eatables kept inside at 9^@ C. If room t...

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  12. A system absorbs 2 Kcals heat and does 500 J of work, then internal en...

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  13. If a monoatomic gas at 17^@C is suddenly compressed to 1/8th of initia...

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  14. One mole of an ideal gas at 300 K expands from V to 2V volume, then wo...

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  15. One mole of an ideal gas is heated at constant pressure. If an 100 Jou...

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  16. The efficiency of a carnot engine eta = 1/10. This carnot engine used ...

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  17. A gas at 27^@ C temperature and 30 atmospheric pressure is allowed to ...

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  18. When an ideal diatomic gas is heated at constant pressure, the fractio...

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  19. The molar specific heat at constant pressure of an ideal gas is 7/2R....

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