MECHANISM AND MACHINE MCQ ON GEAR

Q.1 Bevel gears have their teeth____.

A. Curved over the wheel rim

B. Cut on the surface of the frusta of cones

C. Inclined to wheel rim

D. Straight over the wheel rim

Ans-: B

Q.2 The product of circular pitch and diameteral pitch is equal to the _____.

A. Module

B. Unity

C. 1

D. π

Ans-: D

Q.3 A gear whose tooth traces are straight line generators of the cone is called ?

A. Hypoid gear

B. Straight bevel gear

C. Spiral bevel gear

D. None of the above

Ans-: B

Q.4 The tooth traces of the spiral bevel gear are _____.

A. Spiral

B. Straight

C. Curved

D. Zig-zag

Ans-: C

Q.5 Worm gears are generally used when the high speed reduction is required. What is the ratio ?

A. 5:1

B. 1:10

C. 2:5

D. 10:1

Ans-: D

Q.6 The sum of the arc of approach and the arc of recess is known as ___.

A. Arc of action

B. Arc of recess

C. Arc of approach

D. None of the above

Ans-: A

Q.7 The arc measured on pitch circle from the point of beginning of contact to the pitch point is called the ____.

A. Arc of action 

B. Arc of approach

C. Arc of recess

D. All of the above

Ans-: B

Q.8 The acute angle between the tangent to the helix and a plane perpendicular to axis of cylinder is ?

A. Helix angle

B. Base angle

C. Acute angle

D. Lead angle

Ans-: D

Q.9 The acute angle between the tangent to the helix and axis of the cylinder on which teeth are cut is called ?

A. Acute angle

B. Base angle

C. Lead angle

D. Helix angle

Ans-: D

Q.10 Which of the following is not the gear for non- parallel, non- intersecting shafts ?

A. Worm

B. Hypoid

C. Bevel

D. Helical

Ans-: C

multiple choice questions on gears and gear terminology

Q.1 The ratio of number of teeth and pitch circle diameter is called _____.

A. Diameteral pitch

B. Module

C. Pitch

D. Teeth diameter

Ans-: A

Q.2 The pitch circle diameter of an involute gear is dependent of the _____.

A. Base diameter 

B. Tooth thickness

C. Pressure angle

D. Addendum

Ans-: C

Q.3 Which of the following is not a type of gear ?

A. Helical

B. Spur

C. Circular

D. Bevel

Ans-: C

Q.4 Gears are used generally when the centre distances are relatively ____.

A. Short

B. Long

C. Variable

D. Zero

Ans-: A

Q.5 Which gear is a cylindrical whose tooth traces are straight helices i.e.,teeth are inclined at an angle to the gear axis.

A. Spur gear

B. Helical gear

C. Worn gear

D. Bevel gear

Ans-: B

Q.6 Which gear is a spur gear of infinite diameter?

A. pinion

B. Worn gear

C. Herringbone gear

D. Rack

Ans-: D

Q.7 Bevel gears are used to transmit _______ motion between the two shafts.

A. Circular

B. Straight

C. Rotary

D. Reciprocating

Ans-: C

Q.8 The pressure angle for involute gears is ?

A. Zero

B. Variable

C. Depend on size of teeth

D. always constant

Ans-: D

Q.9 If the peripheral velocity of gears lies between 3-15 m/sec then it is called ___.

A. High velocity gear

B. Low velocity gear

C. Medium velocity gear

D. None of the above

Ans-: C

Q.10 Pitch circle is always _____ than the base circle.

A. Bigger 

B. Smaller

C. Equal

D. Constant

Ans-: A

MECHANISM AND MACHINE MCQ -07 ON VIBRATION

Q.1 The motion completed in the time interval of a period is called ____.

A. Period

B. Frequency

C. Cycle

D. Time

Ans-: C

Q.2 In vibration after initial displacement, no external force act and the motion is maintained by the internal elastic forces is called ____________ vibration.

A. Free 

B. Damped

C. Natural

D. Forced 

E. A+ C

Ans-: E

Q.3 The number of complete cycles of motion in a unit interval of time is known as ____.

A. Frequency

B. Time

C. Period

D. Vibration period

Ans-: A

Q.4 The interval of time taken by the motion to repeat itself is known as the _____.

A. Cycle

B. Period

C. Frequency

D. None of the above

Ans-: B

Q.5 Due to the internal and external resistances, the energy processed by the system is gradually dissipated ,such type of vibration is known as the

_____.

A. Free vibration

B. Damped vibration

C. Torsional vibration

D. Forced vibration

Ans-: B

Q.6 When the periodic disturbing force is applied to the body, then vibrations have same frequency as the applied force is called ?

A. Natural vibration

B. Damped vibration

C. Torsional vibration

D. Forced vibration

Ans-: D

Q.7 Resonance is caused when the frequency of the external force coincides with the _____ of the system.

A. Natural vibration 

B. Force

C. Natural frequency

D. Vibration

Ans-: C

Q.8 Which of the following is not a type of vibration?

A. Free

B. Forced

C. Damped

D. Periodic 

Ans-: D

Q.9 If the damping factor for a vibrating system is unity, then the system is called ____ system.

A. Over damped

B. Under damped

C. Critically damped

D. Not damped

Ans-: C

Q.10 In forced vibrations the magnitude of damping force at resonance equals to _____.

A. Zero

B. Impressed force

C. Inertia force

D. Spring force

Ans-: B

MECHANISM AND MACHINE MCQ-06

Q.1 Which of the following is governor used in the gramophone ?

A. Pickening

B. Hartnell

C. Porter

D. Centrifugal

Ans-: A

Q.2 Which of the following is not a flexible coupling ?

A. Muff

B. Oldham's 

C. Universal

D. Bushed pin

Ans-: A

Q.3 Practically the sensitiveness of Watt and porter governor are ?

A. Double

B. Half

C. Same

D. 1/3

Ans-: C

Q.4 The pressure angle for involute gears is ___.

A. Depending on type of meshing

B. Depending on size of teeth

C. Variable

D. Always constant

Ans-: D

Q.5 Flank is the surface of gear tooth ________ the pitch surface.

A. Above

B. Below

C. Constant

D. None of the above

Ans-: B

Q.6 Gear box of a car utilises_______.

A. Simple train

B. Complex train

C. Compound train

D. None of the above

Ans-: C

Q.7 Which gears are used for equal speed?

A. Spur gear

B. Bevel gear

C. Mittre gear

D. All of the above

Ans-: C

Q.8 The transverse section of a helical gear is identical to _____.

A. Bevel gear

B. Worm gear

C. Spur gear

D. Mittre gear

Ans-: C

Q.9 The surface of the gear tooth below the pitch surface is called ____.

A. Face

B. Flank

C. Tooth space

D. Tooth thickness

Ans-: B

Q.10 Muff coupling is a ______ coupling.

A. Non- flexible

B. Flexible

C. Semi flexible

D. Hard

Ans-: A

Mechanical governor and types of governor with working principal

GOVERNORS -: 

Governor is a mechanical part of an engine which maintain a constant mean speed of rotation of the crank shaft over long periods during which the load on engine may vary, by controlling the fuel input. Governor supply the fuel to the engine with variation of load on the engine and maintain constant speed.

WORKING PRINCIPAL OF GOVERNOR -:              The mechanical  governors uses the flyweights to create a force based off of the crankshaft speed which is balanced by the force of governor spring. The top engine speed is varied by the increasing spring force to run faster or decreasing the force to run slower. The governor spring wants to open the throttle and governor tries to close the throttle . The interaction of the governor spring and the mechanical governor holds the throttle at the desired engine rpms based upon a force balance and the load or operating conditions.

There are different types of governors -: 

1. Centrifugal governor.                                              2. Inertia governor.                                                      3. Watt governor.                                                        4. Porter governor.                                                      5. Hartnell governor.

1. Centrifugal governor -:                                          In centrifugal governor, governor balls are caused to revolve about the axis of the shaft. For each speed of rotation there is a fixed position of balls when the centrifugal force is just balanced by the inward controlling force exerted by springs. The movement of the balls is transmitted by governor mechanism to control the amount of the  energy supplied to the engine.

2. Inertia governor -:                                                  In this type of governor the balls are so arranged that the inertia force caused by an angular acce- leration or retardation of the governor shaft tend to alter their position and the displacement of the governor balls being controlled by springs. It has rapid response to the effect of a change of load, because displacement of the balls is proportional to the rate of change of speed of rotation.

3. Watt governor -:                                                      The watt governor height is independent of the weight of the balls and length of the supporting arms of the governor. The height of governor is varies inversely as the square of the speed.             Height " h " = g / w^2.      

STRENGTH OF MATERIAL MCQ-10

Q.1 The ratio of number of teeth and pitch circle diameter is called ?

A. Diameteral pitch

B. Pitch

C. Addendum

D. Module

Ans-: A

Q.2 The circle passing through the bottom of the teeth of gear is known as ____.

A. Prime circle

B. Base circle

C. Dedendum circle

D. Addendum circle

Ans-: C

Q.3 The transverse section of a helical gear is identical to the ______ gear.

A. Bevel

B. Worm

C. Spur 

D. Helical

Ans-: C

Q.4 The difference between the addendum and dedendum is known as ______.

A. Backless

B. Clearance

C. Flank

D. Module

Ans-: B

Q.5 The path of contact in involute gears is a____.

A. Curved line

B. Circle

C. Cycloidal 

D. Straight line

Ans-: D

Q.6 Bevel gears are used to transmit ____ motion between two shafts .

A. Reciprocating

B. Rotary

C. Straight line

D. None of the above

Ans-: B

Q.7  Which of the following are spring loaded type governor?

A. Hartnell

B. Proel

C. Gravity

D. All of the above

Ans-: A

Q.8 Which of the following is gravity controlled type governor?

A. Hartnell

B. Watt 

C. Pendulum

D. Porter

Ans-: D

Q.9 A cam and follower constitute ____ pair.

A. Lower

B. Higher

C. Kinematic

D. Link

Ans-: B

Q.10 A joint of two elements permitting relative motion is called ?

A. Lower pair

B. Higher pair

C. Kinematic pair

D. None of the above

Ans-: C

TERMINOLOGY OF GEAR TOOTH

 Terminology of gear tooth 

1.Base circle -: It us the circle from which involute form is generated. only the base circle on a gear is fixed and unalterable.

2.pitch circle -: It us an imaginary circle most use-ful in calculations. It my be noted that an infinite number of pitch circle can be chosen,each asso-ciated with its own pressure angle.

3.Module -: It is defined as the length of the pitch circle diameter per tooth. Thus, if pitch circle diameter of gear be D and number of teeth n, then module (m) = D/n .

4.Pitch circle diameter-: It is the diameter of a circle which by pure rolling action would produce the same motion as the toothed gear wheel. this the most important diameter in gears.

5.Circular pitch -: It the arc distance measured around the pitch circle from the flank of one tooth to a similar flank in the next tooth.

6.Clearance -: This is the radial distance from the tip of a tooth to the bottom of a mating tooth space when the teeth are symmetrically engaged.

7. Diameteral pitch -: The diameteral pitch can be defined as the number of teeth per inch of the pitch circle diameter.

8. Addendum -: Addendum is the radial distance from the pitch circle to the tip of the tooth.

9. Dedendum -: This is the radial distance from the pitch circle to the bottom of tooth space.

Dedendum = Addendum + Clearance 

                    = 1 m + 0.157 m. = 1.157 m

10. Blank diameter -: This is the diameter of the blank from which gear is cut . It is equal to pitch circle diameter plus twice the addenda.

11. Tooth thickness -: The tooth thickness is the arc distance measured along the pitch circle from its intercept with one flank to it's intercept with the other flank of the same tooth.