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The coefficient of performance of a refrigerator is 5. If the inside temperature of freezer is –20°C, then the temperature of the surroundings to which it rejects heat is
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- 41°C
- 11°C
- 21°C
- 31°C
Correct Option: D
| Coefficient of performance, Cop = | ||
| T1 - T2 |
| 5 = | = | ||
| T1 - (273 - 20) | T1 - 253 |
5T1 – (5 × 253) = 253
5T1 = 253 + (5 × 253) = 1518
| ∴ T1 = | = 303.6 | |
| 5 |
or, T1 = 303.6 – 273 = 30.6 ≅ 31°C
