1. A Carnot engine operating between temperature T, and T ( 4. A train whistling at constant frequency is moving towards a station at a constant speed V. The train goes past a stationary observer on the station. The frequency n' of the sound as heard by observer can be expressed by which of the expected curve as a function of time t? 5. n' (1) (3) n' (2) (4) n' A wave travelling along a string is described by y (x, t) 0.008 sin (62.80x 3.0 t) in which numerical constants are in SI units (0.008 m, 62.80 rad m and 3.0 rad s). What would be the wavelength of the wave? (1) 0.001 m (2) 0.1 m (3) 0.0785 m (4) (4) 0.1256 m