Engineering Questions with Answers - Multiple Choice Questions

# Machine Dynamics MCQ – Gyroscopic Couple

1 - Question

The axis of precession is ____________ to the plane in which the axis of spin is going to rotate.
a) parallel
b) perpendicular
c) spiral
d) none of the mentioned

Explanation: The axis of precession is perpendicular to the plane in which the axis of spin is going to rotate. The gyroscopic principle is used in an instrument or toy known as gyroscope.

2 - Question

A disc is a spinning with an angular velocity ω rad/s about the axis of spin. The couple applied to the disc causing precession will be
a) 1/2 Iω2
b) Iω2
c) 1/2 Iωωp
d) Iωωp

Explanation: None

3 - Question

The engine of an aeroplane rotates in clockwise direction when seen from the tail end and the aeroplane takes a turn to the left. The effect of gyroscopic couple on the aeroplane will be
a) to dip the nose and tail
b) to raise the nose and tail
c) to raise the nose and dip of the tail
d) to dip the nose and raise the tail

Explanation: The engine of an aeroplane rotates in clockwise direction when seen from the tail end and the aeroplane takes a turn to the left. The effect of gyroscopic couple on the aeroplane will be to raise the nose and dip of the tail.
The engine of an aeroplane rotates in clockwise direction when seen from the tail end and the aeroplane takes a turn to the right. The effect of gyroscopic couple on the aeroplane will be to dip the nose and raise the tail.

4 - Question

The engine of an aeroplane rotates in clockwise direction when seen from the tail end and the aeroplane takes a turn to the right. The effect of gyroscopic couple on the aeroplane will be to dip the nose and raise the tail.
a) True
b) False

Explanation: The engine of an aeroplane rotates in clockwise direction when seen from the tail end and the aeroplane takes a turn to the left. The effect of gyroscopic couple on the aeroplane will be to raise the nose and dip of the tail.
The engine of an aeroplane rotates in clockwise direction when seen from the tail end and the aeroplane takes a turn to the right. The effect of gyroscopic couple on the aeroplane will be to dip the nose and raise the tail.

5 - Question

The steering of a ship means
a) movement of a complete ship up and down in vertical plane about transverse axis
b) turning of a complete ship in a curve towards right or left, while it moves forward
c) rolling of a complete ship side-ways
d) none of the mentioned

Explanation: The steering is the turning of a complete ship in a curve towards right or left, while it moves forward.

6 - Question

The rolling of a complete ship side-ways is known as pitching of a ship.
a) True
b) False

Explanation: The pitching is the movement of a complete ship up and down in a vertical plane about transverse axis.

7 - Question

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

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

8 - Question

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.
a) True
b) False

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

9 - Question

The pitching of a ship is assumed to take place with simple harmonic motion.
a) True
b) False

Explanation: None.

10 - Question

When the pitching of a ship is upward, the effect of gyroscopic couple acting on it will be
a) to move the ship towards star-board
b) to move the ship towards port side
c) to raise the bow and lower the stern
d) to raise the stern and lower the bow