Theory Of Machine - Practice Test

[#386] The equation of free vibrations of a system is $$frac{{{{ ext{d}}^2}{ ext{x}}}}{{{ ext{d}}{{ ext{t}}^2}}} + 36{pi ^2}{ ext{x}} = 0{ ext{,}}$$ xa0 xa0its natural frequency is

(A) 3Hz

(B) $$3pi { ext{Hz}}$$

(C) 6Hz

(D) $$6pi { ext{Hz}}$$

Correct Answer

(A) 3Hz

[#387] A rotor supported at A and B carries two masses as shown in the below figure. The rotor is

(A) Dynamically balanced

(B) Statically balanced

(C) Statically and dynamically balanced

(D) Not balanced

Correct Answer

(C) Statically and dynamically balanced

Explanation

Solution:

[#388] According to Kennedy's theorem, if three bodies have plane motions, their instantaneous centers lie on

(A) A triangle

(B) A point

(C) Two lines

(D) A straight line

Correct Answer

(D) A straight line

[#389] The amplitude of vibration is always __________ the radius of the circle.

(A) Equal to

(B) Less than

(C) Greater than

(D) None of these

Correct Answer

(A) Equal to

[#390] The Bifilar suspension method is used to determine

(A) Natural frequency of vibration

(B) Position of balancing weights

(C) Moment of inertia

(D) Centripetal acceleration

Correct Answer

(C) Moment of inertia

Theory Of Machine - Study Mode

[#386] The equation of free vibrations of a system is $$frac{{{{ ext{d}}^2}{ ext{x}}}}{{{ ext{d}}{{ ext{t}}^2}}} + 36{pi ^2}{ ext{x}} = 0{ ext{,}}$$ xa0 xa0its natural frequency is

Correct Answer

[#387] A rotor supported at A and B carries two masses as shown in the below figure. The rotor is

Correct Answer

Explanation

[#388] According to Kennedy's theorem, if three bodies have plane motions, their instantaneous centers lie on

Correct Answer

[#389] The amplitude of vibration is always __________ the radius of the circle.

Correct Answer

[#390] The Bifilar suspension method is used to determine

Correct Answer