A refrigerator works between temperature of melting ice and room temperatures (17° C ). The amount of energy in kWh that must be supplied to freeze 1 kg of water at 0° C is

Question

A refrigerator works between temperature of melting ice and room temperatures (17° C ). The amount of energy in kWh that must be supplied to freeze 1 kg of water at 0° C is (A) 1.4 (B) 1.8 (C) 0.058 (D) 2.5

Tardigrade Admin · Accepted Answer

Given, T2=0° C =273 K , T1=17° C =17+273=290 K COP =( Q 2/W)=(T2/T1-T2) ⇒ (80 × 1000 × 4.2/W) =(273/290-273)=(273/17) W=(80 × 1000 × 4.2 × 17/273) J W=(33.6 × 17 × 104/273 × 3.6 × 105) kWh =0.058 kWh

Q. A refrigerator works between temperature of melting ice and room temperatures (17∘C). The amount of energy in kWh that must be supplied to freeze 1kg of water at 0∘C is

1.4

1.8

0.058

2.5

Given, T2​=0∘C=273K, T1​=17∘C=17+273=290K COP=WQ2​​=T1​−T2​T2​​ ⇒W80×1000×4.2​=290−273273​=17273​ W=27380×1000×4.2×17​J W=273×3.6×10533.6×17×104​kWh =0.058kWh

Q. A refrigerator works between temperature of melting ice and room temperatures $(1 7^{\circ} C)$ . The amount of energy in $kWh$ that must be supplied to freeze $1 k g$ of water at $0^{\circ} C$ is