Find the efficiency of a motor vehicle engine if at a speed of 45km/ h

the engine consumes 12 litres of

petrol per

100km

and develops a power of

16hp

. The density of the petrol is

0.8g / cm . The heat

value of petrol is

45kJ / g

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?