A Carnot engine whose sink is at 300 K has an efficiency

A Carnot engine whose sink is at 300 K has an efficiency of 40%. By how much should the temperature of source be increased so as to increase, its efficiency by 50% of original efficiency ?

We know that efficiency of Carnot Engine

=	T₁ - T₂
	T₁

where, T₁ is temp. of source & T₂ is temp. of sink

∴ 0.40 =	T₁ - 300	⇒ T₁ - 300 = 0.40T₁
	T₁

0.6T₁ = 300 ⇒ T₁ =	300	=	3000	= 500 K
	0.6		6

Now efficiency to be increased by 50%

∴ 0.60 =	T₁ - 300	⇒ T₁ - 300 = 0.6T₁
	T₁

0.4T₁ = 300 ⇒ T₁ =	300	=	300 × 10	= 750 K
	0.4		4

Increase in temp = 750 – 500 = 250 K