Engineering :: Thermodynamics

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321.

Which two cycles have one constant volume, one constant pressure and two adiabatic processes each?

A.	Diesel and Dual cycles	B.	Brayton and Joules cycle
C.	Sterling and Diesel cycles	D.	Otto and Carnot cycles

322.

A scavenging pump is used in

A.	four stroke compression ignition engines	B.	steam engines
C.	two stroke spark ignition engines	D.	vapour compression cycles

323.

During an adiabatic expansion, the increase in volume is associated with

A.	Decrease in pressure and decrease in temperature	B.	decrease in pressure and increase in temperature
C.	increase in pressure and decrease in temperature	D.	increase in pressure and increase in temperature

324.

According to Boyle's law PV = C when the temperature is constant. In this relation the magnitude of C depends upon

A.	quantity of the gas involved	B.	molecular weight of the gas
C.	atomicity of the gas	D.	atmospheric pressure

325.

A gas (inversion temperature Ti) undergoing Joule Thomson expansion at temperature T will produce cooling effect only when

A.	Ti = T	B.	Ti > T
C.	Ti < T

326.

If the sun becomes twice as hot

A.	its output of radiation energy will fall	B.	it will disintegrate into fragments
C.	it will radiate predominantly in infra-red	D.	it will radiate predominantly ultraviolet

327.

Which of the following is not a characteristic of liquid air?

A.	It has no surface tension	B.	It will freeze mercury and ammonia
C.	It will cause rubber to become brittle	D.	It will separate out lead from solder

328.

Theoretically in a petrol engine during which stroke both suction as well as exhaust valves will remain closed?

A.	Suction stroke	B.	Exhaust stroke
C.	Both suction and exhaust strokes	D.	None of the above

329.

The area inside the PV diagram for a diesel engine represents

A.	heat supplied	B.	work supplied
C.	work done	D.	change in entropy

330.

Three engines A, B and C operating on Carnot cycle use working substances as oxygen, hydrogen and air. Which engine will have higher efficiency?

A.	Angine A	B.	Engine B
C.	Engine C	D.	All will have the same efficiency