1. A flywheel of moment of inertia 9.8 kg.m^{2} fluctuates by 30 rpm for a fluctuation in energy of 1936 Joules. The mean speed of the flywheel is (rpm)
(a) 600
(b) 900
(c) 968
(d) 29470
(2 Mark, 1998)

Ans: a
2. Which of the following statement is correct?
(a) Flywheel reduces speed fluctuations during a cycle for a constant load, but flywheel does not control the mean speed of the engine if the load changes.
(b) Flywheel does not reduce speed fluctuation during a cycle for a constant load, but flywheel does not control the mean speed of the engine if the load changes.
(c) Governor controls speed fluctuations during a cycle for a constant load, but governor does not control the mean speed of the engine if the load changes.
(d) Governor controls speed fluctuations during a cycle for a constant load, and governor also control the mean speed of the engine if the load changes.
(1 Mark, 2001)

Ans: a
3. For a certain engine having an average speed of 1200 rpm, a flywheel approximated as a solid disc, is required for keeping the fluctuation of speed within 2% about the average speed. The fluctuation of kinetic energy per cycle is found to be 2 kJ. What is the least possible mass of the flywheel if its diameter is not exceed 1 m ?
(a) 40 kg
(b) 51 kg
(c) 62 kg
(d) 73 kg
(2 Mark, 2003)

Ans: b
4. In a camfollower mechanism, the follower needs to rise through 20 mm during 60° of cam rotation, the first 30° with a constant acceleration and then with a deceleration of the same magnitude. The initial and final speeds of the follower are zero. The cam rotates at a uniform speed of 300 rpm. The maximum speed of the follower is
(a) 0.60 m/s
(b) 1.20 m/s
(c) 1.68 m/s
(d) 2.40 m/s
(2 Mark, 2005)

Ans: b
4. A rotating disc of 1 m diameter has two eccentric masses of 0.5 kg each at radii of 50 mm and 60 mm at angular positions of 0° and 150°, respectively. A balancing mass of 0.1 kg is to be used to balance the rotor. What is the radial position of the balancing mass?
(a) 50 mm
(b) 120 mm
(c) 150 mm
(d) 280 mm
(2 Mark, 2005)

Ans: c
5. If C_{f} is the coefficient of speed fluctuation of a flywheel then the ratio of a flywheel then the ratio of ω_{max}/ω_{min} will be
(a) \frac { 12{ C }_{ f } }{ 1+2{ C }_{ f } }
(b) \frac { 22{ C }_{ f } }{ 1+2{ C }_{ f } }
(c) \frac { 1+2{ C }_{ f } }{ 12{ C }_{ f } }
(d) \frac { 2+{ C }_{ f } }{ 2{ C }_{ f } }
(2 Mark, 2006)

Ans: d
6. The speed of an engine varies from 210 rad/s to 190 rad/s. During the cycle the change in kinetic energy is found to be 400 Nm. The inertia of the flywheel in kg.m^{2} is
(a) 0.10
(b) 0.20
(c) 0.30
(d) 0.40
(2 Mark, 2007)

Ans: a
7. In a cam design, the rise motion is given by a simple harmonic motion s = \frac { h }{ 2 } \left( 1cos\frac { \pi \theta }{ \beta } \right), where h is total rise, θ is camshaft angle, β is the total angle of the rise interval. The jerk is given by
(a) \frac { h }{ 2 } \left( 1cos\frac { \pi \theta }{ \beta } \right)
(b) \frac { \pi }{ \beta } \frac { h }{ 2 } sin\left( \frac { \pi \theta }{ \beta } \right)
(c) \frac { { \pi }^{ 2 } }{ { \beta }^{ 2 } } \frac { h }{ 2 } cos\left( \frac { \pi \theta }{ \beta } \right)
(d) \frac { { \pi }^{ 2 } }{ { \beta }^{ 2 } } \frac { h }{ 2 } sin\left( \frac { \pi \theta }{ \beta } \right)
(2 Mark, 2008)

Ans: d
8. A cantilever type gate hinged at Q is shown in the figure. P and R are the centers of gravity of the cantilever part and the counterweight respectively. The mass of the cantilever part is 75 kg. The mass of the counterweight, for static balance, is
(a) 75 kg
(b) 150 kg
(c) 225 kg
(d) 300 kg
(1 Mark, 2008)

Ans: d
9. A flywheel connected to a punching machine has to supply energy of 400 Nm while running at a mean angular speed of 20 rad/s. If the total fluctuation of speed is not to exceed ±2%, the mass moment of inertia of the flywheel in kgm^{2} is
(a) 25
(b) 50
(c) 100
(d) 125
(2 Mark, 2013)

Ans: a
10. A slider crank mechanism has slider mass of 10 kg, stroke of 0.2 m and rotates with a uniform angular velocity of 10 rad/s. The primary inertia forces of the slider are partially balanced by a revolving mass of 6 kg at the crank, placed at a distance equal to crank radius. Neglect the mass of connecting rod and crank. When the crank angle (with respect to slider axis) is 30°, the unbalanced force (in newton) normal to the slider axis is ______.
(2 Mark, 2014[1])

Ans: 30
11. Consider a rotating disk cam and a translating roller follower with zero offset. Which one of the following pitch curves, parameterized by t, lying in the interval 0 to 2π, is associated with the maximum translation of the follower during one full rotation of the cam rotating about the center at (x, y) = (0, 0) ?
(a) x (t) = cos t, y (t) = sin t
(b) x (t) = cos t, y (t) = 2sint
(c) x (t) = \frac { 1 }{ 2 } + cos t, y (t) = 2sint
(d) x (t) = \frac { 1 }{ 2 } + cos t, y (t) = sint
(2 Mark, 2014[3])

Ans: c
12. Maximum fluctuation of kinetic energy in an engine has been calculated to be 2600 J. Assuming that the engine runs at an average speed of 200 rpm, the polar mass moment of inertia (in kg.m^{2}) of a flywheel to keep the speed fluctuation within ±0.5% of the average speed is ______.
(2 Mark, 2014[2])

Ans: 592.7
13. Torque and angular speed data over one cycle for a shaft carrying a flywheel are shown in the figures. The moment of inertia (in kg.m^{2}) of the flywheel is ___.
(2 Mark, 2014[4])

Ans: 31.4
14. The torque (in Nm) exerted on the crank shaft of a two stroke engine can be described as 𝑇 =10000 +1000 sin2θ −1200 cos2θ, where θ is the crank angle as measured from inner dead center position. Assuming the resisting torque to be constant, the power (in kW) developed by the engine at 100 rpm is _____.
(2 Mark, 2015[3])

Ans: 104.719
15. A car is moving on a curved horizontal road of radius 100 m with a speed of 20 m/s. The rotating masses of the engine have an angular speed of 100 rad/s in clockwise direction when viewed from the front of the car. The combined moment of inertia of the rotating masses is 10 kgm^{2}. The magnitude of the gyroscopic moment (in Nm) is _____.
(2 Mark, 2016[1])

Ans: 200
16. Two masses m are attached to opposite sides of a rigid rotating shaft in the vertical plane. Another pair of equal masses m_{1} is attached to the opposite sides of the shaft in the vertical plane as shown in figure. Consider m = 1 kg, e = 50 mm, e_{1} = 20 mm, b = 0.3 m, a = 2 m and a_{1} = 2.5 m. For the system to be dynamically balanced, m_{1} should be ______ kg.
(2 Mark, 2016[3])

Ans: 2
17. Three masses are connected to a rotating shaft supported on bearing A and B as shown in the figure. The system is in a space where the gravitational effect is absent. Neglect the mass of shaft and rods connecting the masses. For m_{1} = 10 kg, m_{2} = 5kg and m_{3} = 2.5 kg and for a shaft angular speed of 1000 radians/s, the magnitude of the bearing reaction (in N) at location b is ____.
(2 Mark, 2017[2])

Ans: 0
18. In a camfollower, the follower rises by h as the cam rotates by δ (radians) at constant angular velocity ω (radians/s). The follower is uniformly accelerating during the first half of the rise period and it is uniformly decelerating in the latter half of the rise period. Assuming that the magnitudes of the acceleration and deceleration are same, the maximum velocity of the follower is
(a) \frac { 4h\omega }{ \delta }
(b) hω
(c) \frac { 2h\omega }{ \delta }
(d) 2hω
(2 Mark, 2018[2])

Ans: c
19. A flatfaced follower is driven using a circular eccentric cam rotating at a constant angular velocity ω. At time t = 0, the vertical position of the follower is y(0) = 0, and the system is in the configuration shown below
The vertical position of the follower face, y(t) is given by
(a) eSinωt
(b) e(1 + 2cosωt)
(c) e(1 – cosωt)
(d) eSin2ωt
(1 Mark, 2019[1])

Ans: c
20. The rotor of turbojet engine of an aircraft has a mass 180 kg and polar moment of inertia 10 kg.m^{2} about the rotor axis. The rotor rotates at a constant speed of 1100 rad/s in the clockwise direction when viewed from the front of the aircraft. The aircraft while flying at a speed of 800 km per hour takes a turn with a radius of 1.5 km to the left. The gyroscopic moment exerted by the rotor on the aircraft structure and the direction of motion of the nose when the aircraft turns, are
(a) 1629.6 N.m and the nose goes up
(b) 1629.6 N.m and the nose goes down
(c) 162.9 N.m and the nose goes up
(d) 162.9 N.m and the nose goes down
(2 Mark, 2019[1])

Ans: b
21. Two masses A and B having mass m_{a} and m_{b} , respectively, lying in the plane of the figure shown, are rigidly attached to a shaft which revolves about an axis through O perpendicular to the plane of the figure. The radii of rotation of the masses m_{a} and m_{b} are r_{a} and r_{b}, respectively. The angle between lines OA and OB is 90°. If m_{a} = 10 kg, m_{b} = 20 kg, r_{a} = 200 mm and r_{b} =400 mm, then the balance mass to be placed at a radius of 200 mm is ____ kg (round off to two decimal places).
(2 Mark, 2019[2])

Ans: 41.23
22. A uniform disc with radius r and a mass of m kg is mounted centrally on a horizontal axle of negligible mass and length of 1.5r.
The disc spins counterclockwise about the axle with angular speed ω, when viewed from the righthand side bearing, Q. The axle precesses about a vertical axis at ω_{P} = ω/10 in the clockwise direction when viewed from above. Let R_{P} and R_{Q} (positive upwards) be the resultant reaction forces due to the mass and the gyroscopic effect, at bearings P and Q, respectively. Assuming ω^{2}r = 300 m/s^{2} and g = 10m/s^{2}, the ratio of the larger to the smaller bearing reaction force (considering appropriate signs) is _____.
(2 Mark, 2019[2])

Ans: 3