1) Calculate gyroscopic couple acting on a disc which has radius of 135 mm. Angular and precessional velocities are 15 rad/sec and 7 rad/sec respectively.
Assume density = 7810 kg/m3 and thickness of disc = 30 mm
a. 12.83 N-m
b. 10.99 N-m
c. 11 N-m
d. Incomplete data
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Answer
Explanation
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ANSWER: 12.83 N-m
Explanation:
No explanation is available for this question!
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2) Gyroscopic effect is not observed in which of the following actions performed by the ships?
a. Rolling
b. Pitching
c. Steering
d. All of the above
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Answer
Explanation
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ANSWER: Rolling
Explanation:
No explanation is available for this question!
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3) What is meant by pitching of ship?
a. up and down motion of bow and stern along transverse axis
b. up and down motion of bow and stern along longitudinal axis
c. up and down motion of port and starboard along transverse axis
d. none of the above
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Answer
Explanation
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ANSWER: up and down motion of bow and stern along transverse axis
Explanation:
No explanation is available for this question!
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4) Calculate reactive gyroscopic couple acting on rotating disc which is inclined at an angle of 1.5o. Mass moment of inertia about polar and diametral axis is 2.45 kg-m2 and 0.5 kg-m2 respectively. The disc rotates at an angular velocity of 130 rad/sec
a. 800.36 N-m
b. 862.36 N-m
c. 850.11 N-m
d. None of the above
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Answer
Explanation
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ANSWER: 862.36 N-m
Explanation:
No explanation is available for this question!
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5) What is the effect of reactive gyroscopic couple when aeroplane takes right turn and propeller rotates in clockwise direction?
a. The tail of the aeroplane is dipped and nose is raised
b. The tail of the aeroplane is raised and nose is dipped
c. Reactive gyroscopic couple has no effect when propeller rotates in clockwise direction
d. None of the above
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Answer
Explanation
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ANSWER: The tail of the aeroplane is raised and nose is dipped
Explanation:
No explanation is available for this question!
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6) What is the effect of reactive gyroscopic couple when an aeroplane takes a right turn and propeller rotates in anticlockwise direction?
a. The nose and tail of the aeroplane are in horizontal plane
b. The nose of the aeroplane is raised and tail is dipped
c. The nose of the aeroplane is dipped and tail is raised
d. None of the above
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Answer
Explanation
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ANSWER: The nose of the aeroplane is dipped and tail is raised
Explanation:
No explanation is available for this question!
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7) What is the gyroscopic couple acting on the disc which has mass moment of inertia equal to 0.02135 kg-m2. If disc has a speed of 500 rpm and is made to precess at 100 rpm.
a. 13.21 N-m
b. 11.70 N-m
c. 10.23 N-m
d. Incomplete data
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Answer
Explanation
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ANSWER: 11.70 N-m
Explanation:
No explanation is available for this question!
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8) Which of the following statements is/are false for active gyroscopic couple?
a. Reactive gyroscopic couple and active gyroscopic couple are opposite in direction
b. In right hand rule, curled fingers denote direction of precession
c. In active gyroscopic couple spin vector and precession vector are parallel to each other
d. All the statements are false
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Answer
Explanation
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ANSWER: In active gyroscopic couple spin vector and precession vector are parallel to each other
Explanation:
No explanation is available for this question!
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9) How is the direction of precession vector decided by right hand rule?
a. Thumb denotes direction of precession vector
b. Curled fingers denote direction of precession vector
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Answer
Explanation
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ANSWER: Thumb denotes direction of precession vector
Explanation:
No explanation is available for this question!
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10) Degree of freedom for gyroscope rotor is
a. 1
b. 2
c. 3
d. 5
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Answer
Explanation
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ANSWER: 3
Explanation:
No explanation is available for this question!
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