MCQOPTIONS

Explore topic-wise MCQs in Physics.

This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.

1.	When the nozzle operates with the maximum mass flow, the nozzle is said to be
A.	underdamping
B.	overdamping
C.	choked
D.	none of these
Answer» D. none of these

2.	The effect of supersaturation is that the
A.	exit velocity of steam reduces
B.	entropy and specific volume of the steam increases
C.	mass of the steam discharged increases
D.	all of these
Answer» E.

3.	In an impulse turbine
A.	the steam is expanded in nozzles only and there is a pressure drop and heat drop
B.	the pressure and temperature of steam remains constant
C.	the steam is expanded both in fixed and moving blades continuously
D.	the steam is expanded in moving blades only
Answer» B. the pressure and temperature of steam remains constant

4.	De-Laval turbines are mostly used
A.	where low speeds are required
B.	for small power purposes and low speeds
C.	for large power purposes
D.	for small power purposes and high speeds
Answer» E.

5.	The effect of friction on the flow of steam through a nozzle is to
A.	increase the mass flow rate and to increase the exit temperature
B.	decrease the mass flow rate and to increase the wetness of steam
C.	decrease the mass flow rate and to decrease the wetness of steam
D.	increase the exit temperature without any effect on mass flow rate
Answer» D. increase the exit temperature without any effect on mass flow rate

6.	Stage efficiency is also known as
A.	nozzle efficiency
B.	gross efficiency
C.	diagram efficiency
D.	none of these
Answer» C. diagram efficiency

7.	In an ideal impulse turbine, the
A.	relative velocity at the inlet of the moving blade is equal to that at the outlet
B.	absolute velocity at the inlet of moving blade is equal to that at the outlet
C.	axial velocity at inlet is equal to that at the outlet
D.	whirl velocity at inlet is equalto that at the outlet
Answer» B. absolute velocity at the inlet of moving blade is equal to that at the outlet

8.	In a nozzle, the effect of supersaturation is to
A.	decrease specific volume of steam
B.	decrease dryness fraction of steam
C.	increase the entropy
D.	increase the heat drop
Answer» D. increase the heat drop

9.	The process of maintaining the speed of the turbine constant for various load conditions, is known as
A.	reheating
B.	bleeding
C.	none of these
D.	governing
Answer» E.

10.	Which of the following statement is correct for steam turbines as compared to reciprocating steam engines?
A.	all of these
B.	A steam turbine develops higher speeds
C.	The steam consumption is less
D.	The efficiency of steam turbine is higher
Answer» B. A steam turbine develops higher speeds

11.	The compounding of turbines is done in order to
A.	reduce speed of rotor
B.	reduce exit losses
C.	improve efficiency
D.	all of these
Answer» E.

12.	The ratio of the workdone on the blades per kg of steam to the total energy supplied per stage per kg of steam is called
A.	stage efficiency
B.	nozzle efficiency
C.	mechanical efficiency
D.	blading efficiency
Answer» B. nozzle efficiency

13.	The density of supersaturated steam is about __________ that of the ordinary saturated vapour at the corresponding pressure.
A.	2 times
B.	8 times
C.	same as
D.	4 times
Answer» C. same as

14.	A single stage impulse turbine with a diameter of 1.2 m runs at 3000 r.p.m. If the blade speed ratio is 0.42, then the inlet velocity of steam will be
A.	79 m/s
B.	450 m/s
C.	900 m/s
D.	188 m/s
Answer» C. 900 m/s

15.	The impulse turbine rotor efficiency will have a maximum value of 0.5 cos2 ?, where ? is the nozzle exit flow angle, if the
A.	blade velocity coefficient is unity
B.	blades are equiangular and frictionless
C.	blades are equiangular
D.	blade solidity is 0.65
Answer» C. blades are equiangular