Let η 1 is the efficiency of an engine at T 1 = 447 ° C and T 2 = 147 ° C while η 2 is the efficiency at T 1 = 947 ° C and T 2 = 47 ° C . The ratio η 1 η 2 will be

Step-by-step solution

The efficiency of an engine is given by η = 1 - T L T H . Here, T L and T H are in Kelvin scale. ⇒ η 1 = 1 - 147 + 273 447 + 273 = 1 - 420 720 ⇒ η 1 = 300 720 And η 2 = 1 - 47 + 273 947 + 273 = 1 - 320 1220 ⇒ η 2 = 900 1220 ⇒ η 1 η 2 = 300 720 × 1220 900 = 122 72 × 3 ⇒ η 1 η 2 = 0 . 56