The door of a running refrigerator inside a room was left open____________________?

WhiCh of the following statements is correct ?


D. None of these

A diathermic wall is one which____________________?

A. Prevents thermal interaction
B. Permits thermal interaction
C. Encourages thermal interaction
D. Discourages thermal interaction

A manufacturer claims to have a heat engine capable of developing 20 h.p. by receiving heat input of 400 kcal/mt and working between the temperature limits of 227° C and 27° C. His claim is__________________?

A. Justified
B. Not possible
C. May be possible with lot of sophistications
D. Cost will be very high

An engine operates between temperatures of 900°Kandr2 and another engine between T2 and 400°K For both to do equal work, value of T2 will be________________?

A. 650°k
B. 600°k
C. 625°k
D. 700°k

Carnot cycle efficiency depends upon________________?

A. Properties of the medium/substance used
B. Condition of engine
C. Working condition
D. Temperature range of operation

If a system after undergoing a series of processes, returns to the initial state then__________________?

A. Process is thermodynamically in equilibrium
B. Process is executed in closed system cycle
C. Its entropy will change due to irreversibility
D. Sum of heat and work transfer will be zero

Carnot cycle has maximum efficiency for__________________?

A. Reversible engine
B. Irreversible engine
C. New engine
D. Petrol engine

First law of thermodynamics___________________?

A. enables to determine change in internal energy of the system
B. does not help to predict whether the system will or not undergo a change
C. does not enable to determine change in entropy
D. provides relationship between heat, work and internal energy

According to first law of thermodynamics_______________________?

A. Mass and energy are mutually convertible
B. Carnot engine is most efficient
C. Heat and work are mutually convertible
D. Mass and light are mutually convertible

In an isothermal process, the internal energy________________?

A. Increases
B. Decreases
C. Remains constant
D. First increases and then decreases