ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2019

A helical spring has N turns of coil diameter D and a second spring, made of same wire diameter and same material, has N/2 turns of coil of diameter 2D. If the stiffness of the first spring is k, then the stiffness of the second spring will be

A rigid rod PQ shown in Figure is connected to two sliders at each end through pins. The slider can slide along PR and QR. If the velocity of the slider at P is 4 m/s, the velocity of the midpoint of the rod PQ at this instant is

A concentrated mass m is attached at centre of a rod of length 2 L as shown in figure. The rod is kept in a horizontal equilibrium position by a spring of stiffness 4 k. For very small amplitude of vibration, neglecting the weight of the rod and spring, the undamped natural frequency ($$w_n$$) of the system is

At the time of starting, idling and low speed operation, the carburetor supplies a mixture which can be termed as

The crank radius of a single cylinder IC engine is $$\left(\frac{6}{\pi}\right)$$ mm and diameter of the cylinder is 40 mm. The swept volumeof the cylinder in cm$$^3$$ is

For the same values of peak pressure, peak temperature and heat rejection, the correct order of efficiencies for Otto, Duel and Diesel cycles

For determining the ignition quality of compression ignition engine fuels, the reference fuels used are

Air enters diesel engine with a density of 1 kg/m$$^3$$. The compression ratio is 21. At steady state, the air intake is $$21 \times 10^{-3}$$ kg/s and the network output is 20 kW. The Mean effective pressure (kPa) is

The purpose of providing supercharging for engine is

While designing refrigeration systemof anaircraft, the prime consideration is that