1. The area of the indicator diagram represents the magnitude of the
a) net heat transfer by the system
b) net work done on the system
c) net work done by the system
d) none of the mentioned
Explanation: It is the work done in one engine cycle.
2. For Pm=(Ad/Ld)*K, which of the following is true?
a) Pm=mean effective pressure
b) Ad and Ld are area of diagram and length of diagram respectively
c) K id the indicator spring constant
d) all of the mentioned
Explanation: This formula comes from the indicator diagram.
3. The power available at crankshaft is always _____ indicated power.
a) more
b) less
c) equal
d) none of the mentioned
Explanation: Due to friction.
4. Mechanical efficiency of engine is given by
a) IP/BP
b) 1/(BP*IP)
c) (BP*IP)
d) BP/IP
Explanation: Brake power is less than indicated power and mechanical efficiency is given by BP/IP.
5. An engine is said to be double-acting, if the working fluid is made to work on both sides of the piston.
a) true
b) false
Explanation: Such an engine develops twice the amount of work developed in a single-acting engine.
6. The current flow, I, in amperes, is given by I=(dC)/(dτ)
a) dC is the charge crossing a boundary
b) time taken is dτ
c) c is the charge in coulombs and t is time in seconds
d) all of the mentioned
Explanation: This current flow is responsible for the work transfer.
7. Shaft uses which kind of motion to do work?
a) vertical motion
b) horizontal motion
c) rotational motion
d) none of the mentioned
Explanation: When a shaft is rotated by a motor, there is work transfer into the system.
8. Shaft work is given by
a) T*ω
b) T*dθ
c) T*τ
d) none of the mentioned
Explanation: Shaft power is the rate if doing shaft work.
9. The flow work is significant only in
a) flow process
b) open system
c) flow process & open system
d) none of the mentioned
Explanation: Condition for the flow work.
10. Flow work is analogous to
a) shaft work
b) electrical work
c) stirring work
d) displacement work
Explanation: Flow work is the displacement work done at the moving system boundary.