An ideal gas undergoes four different processes from the same initial state (Fig. 12.1). Four processes are adiabatic, isothermal, isobaric and isochoric. Out of 1, 2, 3 and 4 which one is adiabatic.

(a) 4

(b) 3

(c) 2

(d) 1

An ideal engine whose efficiency is 40%, receives heat at 500 K. If required efficiency is 50%, then intake temperature for the same exhaust temperature is

Choose the correct statement.

Two waves of wavelength 50 cm and 51 cm produced 12 beats per second. The velocity of sound is

A gas undergoes a cyclic process ABCA as shown. Find the work done by the gas for

8 moles of oxygen and 4 moles of nitrogen are at same temperature T and are mixed. The total internal energy is