Gyroscopic Couple and Precessional Motion topics include: Precessional angular motion, gyroscopic couple, effect of gyroscopic couple on aeroplane and naval ship, stability of four wheel and two wheel while taking turns, gyroscopic couple effects. A gyroscopic couple is a force that causes a rotating object to tilt perpendicularly. Precessional motion is the movement that results when an object's axis of rotation changes direction without any external torque applied.  A gyroscopic couple is also known as gyroscopic torque. It's the torque or turning force created by a spinning gyroscope... Show more

Gyroscopic Couple and Precessional Motion topics include: Precessional angular motion, gyroscopic couple, effect of gyroscopic couple on aeroplane and naval ship, stability of four wheel and two wheel while taking turns, gyroscopic couple effects.

A gyroscopic couple is a force that causes a rotating object to tilt perpendicularly. Precessional motion is the movement that results when an object's axis of rotation changes direction without any external torque applied. 

A gyroscopic couple is also known as gyroscopic torque. It's the torque or turning force created by a spinning gyroscope when it experiences an external force. This phenomenon arises due to the conservation of angular momentum. 
Precession is the motion of the direction of initial angular momentum. The axis about which precession takes place is known as the axis of precession. 
The phenomenon of gyroscopic precession is studied within the framework of Frenet-Serret formalism adapted to quasi-Killing trajectories.

Precessional motion is a combination of a spinning top's steady circular motion and its spin motion about the axis. 

Precession is a slow, continuous change in the orientation of a spinning body's rotational axis. It is caused by torque applied to the body along its axis of rotation. For example, the smooth, slow circling of a spinning top is precession, while the uneven wobbling is nutation. 

The Earth is affected by two different types of precession: axial precession and apsidal precession. The Earth's precession cycle is approximately 25,700 years. 
Some effects of the Earth's precession include:
Changing pole star
Polar shift and equinoxes shift 

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Machine Dynamics Practice Test: Gyroscopic Couple and Precessional Motion

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25 Questions

1. Which of the following relation is correct regarding the net gyroscope couple C acting on a four wheel vehicle?

ωw.ωp (4 Iw ± G.Ie)ωw.ωp (4 Iw ± G.Ie)2ωw2(4 Iw ± G.Ie)ωw.ωp (4 Iw* G.Ie)

2. The steering of a ship means

rolling of a complete ship side-waysmovement of a complete ship up and down in vertical plane about transverse axisnone of theseturning of a complete ship in a curve towards right or left, while it moves forward

3. Overturning couple is independent of the track width.

TrueFalseMaybeDon't Know

4. A power screw is rotated at constant angular speed of 1.5 revolutions/sec by applying a steady torque of 1.5Nm. How much work is done per revolution? What is the power required?

341.36 W141.36 W441.36 W241.36 W

5. From the following data calculate the gyroscopic couple on the bearing in N-m.
Mass of disc = 30 Kg, diameter = 60 cm
Rotation speed = 1200 rpm
Angle between disc and a plane 90 degree to the axis of shaft = 1°

180190186196

6. If the length and radius of the disc is same them moment of inertia is more about which axis?

ShaftCenterPolarDiametral

7. In the figure given below, the moment of inertia about polar axis OP is _______

2mr2mr2mr2/24mr2

8. Which of the following would change during rolling of a navalship?

Angular velocity of precessionAngular velocity of spinAngular acceleration of precessionNo change occurs

9. When the pitching of a ship is upward, the effect of gyroscopic couple acting on it will be

to raise the bow and lower the sternto move the ship towards star-boardto move the ship towards port sideto raise the stern and lower the bow

10. In latitude 25.0 S, SA (spin axis) of a FG (free gyro) is in position S40E and horizontal. Find the tilt after 6 hours.

61.16 down61.16 up51.15 upnone of these

11. In order to maintain contact between inner wheel and ground the sum of vertical reactions at each of the outer and inner wheels should be less than______

W/4WW/3W/2

12. The overturning couple acting on the four wheeler vehicle is balanced by which of the following forces?

Centrifugal forceHorizontal reactionsCentripetal forceVertical reactions

13. Rolling is the turning of a complete ship in a curve towards left or right, while it moves forward.

TrueDon't KnowMaybeFalse

14. Maximum couple during pitching is given by : (ω: angular velocity of rotor & ωpmax: Maximum angular velocity of precession).

Cmax = I2. ω. ωpmaxCmax = I. ω. ωpmaxCmax = I.(ωpmax)2Cmax = I.(ω)2

15. It is required to lift water at the top of a high building at the rate of 50 litres/min. Assuming the losses due to friction equivalent to 5 m and those due to leakage equal to 5 m head of water, efficiency of pump 90%, decide the kilowatt capacity of motor required to drive the pump.

0.302 kW0.202 kW0.402 kW0.102 kW

16. When the pitching of a ship is upward, the effect of gyroscopic couple acting on it will be

to raise the stern and lower the bowto move the ship towards port sideto raise the bow and lower the sternto move the ship towards starboard

17. The rotor of a ship rotates in clockwise direction when viewed from stern and the ship takes a right turn. The effect of gyroscopic couple acting on it will be to raise the stern and lower the bow.

MaybeTrueDon't KnowFalse

18. Calculate the work done per minute by a punch tool making 20 working strokes per min when a 30 mm diametre hole is punched in 5 mm thick plate with ultimate shear strength og 450 Mpa in each stroke.

30.69 kNm10.69 kNm40.69 kNm20.69 kNm

19. The gyroscope couple does not cause an effect on a naval ship during which of these motions?

SteeringLiftingPitchingRolling

20. What will be the effect of a gyroscopic couple if the axis of precession and axis of spin become parallel?

No effectSteering effectPitchingNo motion

21. In the figure given below, the moment of inertia about diametral axis is _______

m(l2/12 + r2/4)m(l2/12 + r2/2)m(l2/12 + r2)m(l2/6 + r2/4)

22. The axis of precession is ____________ to the plane in which the axis of spin is going to rotate.

parallelspiralperpendicularnone of these

23. When seen from the top, the gyroscopic couple acting on the disc will act in the clockwise direction.

Don't KnowTrueMaybeFalse

24. A disc spinning on its axis at 20 rad/s will undergo precession when a torque 100 N-m is applied about an axis normal to it at an angular speed, if mass moment of inertia of the disc is the 1 kg-m²

10 rad/s20 rad/s2 rad/s5 rad/s

25. Pitching is the movement of a ship up and down in a vertical plane about transverse axis.

MaybeDon't KnowFalseTrue