# Practice Test: Question Set - 14

**1. A single degree of freedom system is given by,**

*m × (d²x/dt²)*+*c × (dx/dt)*+*sx = F.cosω.t*with usual notations. It represents- (A) Free
vibration with damping

- (B) Free
vibration without damping

- (C) Forced
vibration with damping

- (D) Forced
vibration without damping

**2. The factional torque for square thread at the mean radius**

*r*while raising load*W*is given by- (A)

*T*=

*W*.

*r*

*tan(φ - α)*

- (B)

*T*=

*W*.

*r*

*tan(φ*+

*α)*

- (C)

*T*=

*W*.

*r*

*tanα*

- (D)

*T*=

*W*.

*r*

*tanφ*

**3. In a band and block brake, the ratio of tensions on tight side and slack side of the band is (where μ = Coefficient of friction between the blocks and the drum,**

*θ*= Semi-angle of each block subtending at the center of drum, and*n*= Number of blocks)- (A)

*T₁/T₂ =*

*μ. θ. n*

- (B)

*T₁/T₂ = [(1*-

*μ tanθ)*/

*(1*+

*μ*

*tanθ)]*

^{n}

- (C)

*T₁/T₂ =*

*(μ θ)*

^{n}- (D)

*T₁/T₂ =*

*[(1*+

*μ tanθ)/(1 - μ tanθ)]*

^{n}**4. An involute pinion and gear are in mesh. If both have the same size of addendum, then there will be an interference between the**

- (A) Tip
of the gear tooth and flank of pinion

- (B) Tip
of the pinion and flank of gear

- (C) Flanks
of both gear and pinion

- (D) Tip of both
gear and pinion

**5. A universal joint is an example of**

- (A) Higher pair

- (B) Lower pair

- (C) Rolling pair

- (D) Sliding pair

**6. Oldham's coupling is the**

- (A) Second
inversion of double slider crank chain

- (B) Third
inversion of double slider crank chain

- (C) Second
inversion of single slider crank chain

- (D) Third
inversion of slider crank chain

**7. Transmission of power from the engine to the rear axle of an automobile is by means of**

- (A) Compound gears

- (B) Worm
and wheel method

- (C) Hooke's joint

- (D) Crown
gear

**8. Which of the following property of the instantaneous center is correct?**

- (A) A rigid link
rotates instantaneously relative to another link at the instantaneous centre
for the configuration of the mechanism considered.

- (B) The two
rigid links have no linear velocity relative to each other at the instantaneous
centre.

- (C) The velocity
of the instantaneous centre relative to any third rigid link is same whether
the instantaneous centre is regarded as a point on the first rigid link or on
the second rigid link.

- (D) All of the
above

**9. When the addenda on pinion and wheel is such that the path of approach and path of recess are half of their maximum possible values, then the length of the path of contact is given by (where**

*r*= Pitch circle radius of pinion,*R*= Pitch circle radius of wheel, and*φ*= Pressure angle)- (A)

*[(r² + R²) cosφ]/2*

- (B)

*[(r² + R²) sinφ]/2*

- (C)

*[(r + R) cosφ]/2*

- (D)

*[(r + R) sinφ]/2*

**10. A rotor which is balanced statically but not dynamically is supported on two bearings**

*L*apart and at high speed of the rotor, reaction on the left bearing is*R*. The right side of the bearing is shifted to a new position 2*L*apart from the left bearing. At the same rotor speed, dynamic reaction on the left bearing in the new arrangement will- (A) Remain same
as before

- (B) Become equal
to

*2R*

- (C) Become equal
to

*R*

*/2*

- (D) Become equal
to

*R*

*/4*

**11. To transmit power from one rotating shaft to another whose axes are neither parallel nor intersecting, use?**

- (A) Spur gear

- (B) Spiral gear

- (C) Bevel gear

- (D) Worm gear

**12. Hart mechanism has**

- (A) Eight links

- (B) Six links

- (C) Four links

- (D) Twelve links

**13. The dedendum circle diameter is equal to (where, φ = Pressure angle)**

- (A) Pitch circle
dia. ×

*cosφ*

- (B) Addendum
circle dia. ×

*cosφ*

- (C) Clearance
circle dia. ×

*cosφ*

- (D) Pitch circle
dia. ×

*sinφ*

**14. The acceleration of a particle moving with simple harmonic motion, at any instant is given by**

- (A)

*ωx*

- (B)

*ω²x*

- (C)

*ω²/x*

- (D)

*ω³/x*

**15. The equation of motion for a vibrating system with viscous damping is**

**(d²x/dt²) + (c/m). (dx/dt) + (s/m). x = 0****If the roots of this equation are real, then the system will be**

- (A) Over-damped

- (B) Under
damped

- (C) Critically
damped

- (D) Without
vibrations

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