Question

The chart shows data for four heat engines.

Which lists the engines from most efficient to least efficient?

Y, X, W, Z
Z, W, X, Y
Z, X, W, Y
Y, W, X, Z

Answer 1

C.) Z, X,W, Y

Answer 2

efficiency of the heat engine is calculated by the formula

`\eta = 1- (T_c)/(T_h)`

here we know that

`T_c` = cold temperature

`T_h` = hot temperature

now we will find the efficiency of all

1) for W

`\eta_1 = 1- (T_c)/(T_h)`

`\eta_1 = 1- (120)/(620)`

`\eta_1 = 0.806`

2) for X

`\eta_2 = 1- (T_c)/(T_h)`

`\eta_2 = 1- (100)/(840)`

`\eta_2 = 0.88`

3) For Y

`\eta_3 = 1- (T_c)/(T_h)`

`\eta_3 = 1- (300)/(900)`

`\eta_2 = 0.67`

4) for Z

`\eta_4 = 1- (T_c)/(T_h)`

`\eta_4 = 1- (25)/(500)`

`\eta_4 = 0.95`

So here most efficient engine is Z and least is Y

so we can arrange it as

Z > X > W > Y

so 3rd option is correct here