Question And Answer for mechanical Engineer section-20

Q.191. What is ‘Indicated power (I.P)’ ?

Ans. The total power developed by combustion of fuel in the combustion chamber is called indicated power.

Q.192. What is ‘Brake power’ (B.P.) ?

Ans. The power developed by an engine at the output shaft is called the brake power.

Q.193. What is ‘Mechanical efficiency’ ?

Ans. The ratio of B.P. to I.P. is called mechanical efficiency

Q.194. What is ‘Mean effective pressure’ ?

Ans. ‘Mean effective pressure (m.e.p.)’ is defined as hypothetical pressure which is thought to be acting on the piston throughout the power stroke.

Q.195. What is ‘Specific fuel consumption (s.f.c.) ?

Ans. It is the mass of fuel consumed per kW developed per hour, and is a criterion of economical power production.

Q.196. How can speed be measured ?

Ans. The speed may be measured by :
(i) Revolution counters ;
(ii) Mechanical tachometer ;
(iii) Electrical tachometer.

Q.197. Name the methods by which the fuel consumed by an engine can be measured.?

Ans. (i) Fuel flow method ;
(ii) Gravemetric method ;
(iii) Continuous flow meters.

Q.198. Name the methods by which air consumption can be measured.?

Ans. (i) Air box method ;
(ii) Viscous-flow air meter.

Q.199. Name the smoke meters which are used for measurement of smoke.?

Ans. (i) Bosch smoke meter ;
(ii) Hatridge smoke meter ;
(iii) PHS smoke meter.

Q.200. Give the classification of dynamometers used for the measurement of B.P.?

Ans. (i) Absorption dynamometer e.g., Pony brake, Rope brake, Hydraulic brake, Fan brake, Electrical brake ;
(ii) Transmission dynamometers.