# MCQs on Coefficient of Flywheel

1 - Question

Calculate the coefficient of fluctuation of speed if maximum speed is 2500rpm and minimum speed is 1800rpm.

a) 1.44
b) 1.33
c) 0.33
d) 0.44

Explanation: C=2[(Max-Min)/(Max+Min)].

2 - Question

Calculate the coefficient of steadiness if maximum speed of flywheel is 2500rpm and minimum speed is 1800rpm.

a) 3.03
b) 0.33
c) 0.44
d) 3.99

Explanation: C=1.Coeffecient of fluctuation of speed.

3 - Question

Figure1 Answer the questions 3-7 with respect to figure1. Calculate the mean torque T supplied by motor (Torque vs. theta graph of a flywheel is shown above).

a) 3000N-m
b) 1500N-m
c) 2000N-m
d) 2500N-m

Explanation: T[1000+2000/2]x2π/2π.

4 - Question

The point where angular velocity is maximum is?

a) A
b) B
c) C
d) D

Explanation: The flywheel is decelerated in the portion BC and hence rpm is least at C.

5 - Question

The point where velocity of flywheel is maximum is

a) A
b) B
c) C
d) D

Explanation: Flywheel is accelerated in the portion AB and hence velocity is maximum at B

6 - Question

Calculate the energy output from flywheel.

a) 500π
b) 150π
c) 200π
d) 250π

Explanation: U=Area of ΔBCD as max and min velocities are at B and C.

7 - Question

Torque vs. theta graph of a flywheel is shown. Coefficient of fluctuation of speed is 0.2 and the mean angular velocity of the machine is 25 rad/s. Thickness of flywheel is 20mm and density of steel used is 7700kg/mᵌ. Calculate the outer radius of the flywheel.

a) 402mm
b) 202mm
c) 540mm
d) 468mm

Explanation: I=U/ω²C and I=πptR⁴/2.

8 - Question

Figure 2 The turning moment diagram of a multi cylinder engine is shown. The intercepted areas between torque developed by the engine and the mean resisting torque of the machine taken in order from one end are -300,+850 -500, + 900, -550, + 430 and -700 mm². Answer questions 8-13 with respect to figure 2 Calculate the energy at point B if energy assumed at point A is U.

a) U
b) U-300
c) U+300
d) U-150

9 - Question

Calculate the energy at point C if energy at point A is U.

a) U-550
b) None of the listed
c) U+550
d) U+550

Explanation: E=U-300+ 850.

10 - Question

Calculate the energy at point F if energy at A is u.

a) U+340
b) U+260
c) U+400
d) Can’t be determined

Explanation: E=U-300+850-500+900-550.

11 - Question

Calculate the maximum energy.

a) U+1000
b) U+950
c) U+630
d) U+600

Explanation: Maximum energy is at E. E=U-300+850-500+900.

12 - Question

Calculate the point of minimum energy.

a) U+480
b) U+650
c) U-300
d) U-450

Explanation: Minimum energy is at B. E=U-300.

13 - Question

Calculate the net energy output from the flywheel.

a) 1300mm²
b) 1400mm²
c) 1250mm²
d) 1500mm²

Explanation: Maximum energy at E[U+950] and minimum at B[U-300]. Thus net energy=[U+950]-[U-300].

14 - Question

Feather key can be used to prevent axial motion between two elements.

a) True
b) False

Explanation: All types of key but feather key can be used to prevent axial motion between two machine elements.

15 - Question

Keyed joints never lead to stress concentration on shafts.

a) True
b) False