In the given cyclic process from c to b 40 J heat is exchanged from b to a 130 J heat is exchanged and work done is 80 J from a to c, 400 J heat is exchanged, then:

Options

A. Work done in process a to c is 310 J
B. Net work done in cycle is 230 J
C. Net change in internal energy in cycle is 130 J
D. Efficiency of cycle `57.5%`

Answer

A, B, D

Explanation

`DeltaU_(cycl e)=0`
`Q_(n et)=W_(n et)`
`-40-130+400=W_(cb)+W_(ba)+W_(ac)`
`230=0+(-80J)+W_(ac)`
`W_(ac)=310J`
`Thermal efficiency = (Work output)/(Heat input)`
`=230/400xx100=11.5xx5=57.5`