In a simple gear train, if the number of idle gears is odd, then the motion of driven gear will

depend upon the number of teeth on the driving gear

be opposite as that of driving gear

be same as that of driving gear

depend upon the number of teeth on the driving gear

In gears, interference takes place when _____.

Gears do not move smoothly in the absence of lubrication

Tip of a tooth of a mating gear digs into the portion between base and root circles

Gears do not move smoothly in the absence of lubrication

Number of pairs of teeth in contact is given by [where, ϕ = pressure angle]:

(Path of contact)/(Circular pitch)

(Arc of contact)/(Circular pitch)

(Path of contact)/(Circular pitch)

(Arc of contact)/(cos ϕ × Circular pitch)

(Arch of contact × cos ϕ)/(Circular pitch)

In a pair of spur gear with external involute profile, the interference of tooth can be minimized by,

Decreasing centre distance between gear pair

Increasing number of gear teeth

In a Gear Train of n wheels, the speed ratio is defined as

\(\frac{{\mathop N\nolimits_n }}{{\mathop N\nolimits_1 }}\)

\(\frac{{\mathop N\nolimits_1 }}{{\mathop N\nolimits_n }}\)

\(\frac{{\mathop N\nolimits_n }}{{\mathop N\nolimits_1 }}\)

\(\frac{{\mathop T\nolimits_1 }}{{\mathop T\nolimits_n }}\)

\(\frac{{\mathop \omega\nolimits_n }}{{\mathop \omega\nolimits_1 }}\)

Differential gear is used in an automobile to

serves all the three functions as mentioned in 1), 2) and 3) above.

transmit power from the engine to driving wheels.

multiply the available engine torque

enable the vehicle to negotiate the curves properly

serves all the three functions as mentioned in 1), 2) and 3) above.

Power transmitted (Watts) by spur gear may be given as [Ft = tangential component of force (N), Fr = radial component of force (N), n = rotational speed (rpm), and d = pitch diameter (m)]

\({\left( {\frac{{\pi dn}}{{60}}} \right)^2}{F_t}\)

\({\left( {\frac{{\pi dn}}{{60}}} \right)^2}{F_r}\)

A planetary gear train is gear train having

No relative motion of axes and no relative motion of axes with respect to the frame

A relative motion of axes and the axis of at least one of the gears also moves relative to the frame

No relative motion of axes and no relative motion of axes with respect to the frame

no relative motion of axes and the axis of at least one of the gears also moves relative to the frame

a relative motion of axes and none of the axes of gears has relative motion with the frame

60 + Mcqs in Types Gear Trains in Machine Kinematics Page 1 McqOptions

1.	In a simple gear train, if the number of idle gears is odd, then the motion of driven gear will
A.	be opposite as that of driving gear
B.	be same as that of driving gear
C.	depend upon the number of teeth on the driving gear
D.	none of the mentioned
Answer» C. depend upon the number of teeth on the driving gear

Discussion

2.	The circular pitch of a gear is given by
A.	Πd/t
B.	Πd/2t
C.	2Πd/t
D.	Πd/3t
Answer» B. Πd/2t

Discussion

3.	The gear used to convert rotary motion into translating motion is
A.	Worm and wheel
B.	Crown gear
C.	Rack and pinion
D.	Spiral Bevel gear
Answer» D. Spiral Bevel gear

Discussion

4.	For the epicyclic gear arrangement shown in the figure, ω2 = 100 rad/s clockwise (CW) and ωarm = 80 rad/s counter clockwise (CCW). The angular velocity ω5 (in rad/s) is
A.	0
B.	70 CW
C.	140 CCW
D.	140 CW
Answer» D. 140 CW

Discussion

5.	In a simple gear train, 1st gear (Driver) has 40 number of teeth, 2nd gear has 20 number of teeth and last gear has 80 number of teeth. The train value of the gear train is -
A.	0.5
B.	1
C.	2
D.	1.2
Answer» B. 1

Discussion

6.	For ω1 = 60 rpm clockwise (cw) when looked from the left, what is the angular velocity of the carrier and its direction so that Gear 4 rotates in counterclockwise (ccw) direction at twice the angular velocity of Gear 1 when looked from the left
A.	130 rpm, cw
B.	223 rpm, ccw
C.	256 rpm, cw
D.	156 rpm, ccw
Answer» E.

Discussion

7.	In gears, interference takes place when _____.
A.	Tip of a tooth of a mating gear digs into the portion between base and root circles
B.	Gears do not move smoothly in the absence of lubrication
C.	Pitch of the gear is not same
D.	Gear teeth are undercut
Answer» B. Gears do not move smoothly in the absence of lubrication

Discussion

8.	In a reverted gear train, the axes of the first and last gear are:
A.	Neither parallel nor axial
B.	Co-axial
C.	Skew
D.	Parallel
Answer» C. Skew

Discussion

9.	In a compound gear train, gear F rotates in clockwise direction with 200 rpm. Find the rpm and direction of gear A. TA = 20, TB = 80, TC = 25, TD = 50, TE = 20, TF = 50
A.	Clockwise, 4000 rpm
B.	Anticlockwise, 4000 rpm
C.	Anticlockwise, 2000 rpm
D.	Clockwise, 2000 rpm
Answer» C. Anticlockwise, 2000 rpm

Discussion

10.	In a simple Gear Train, driver has 50 teeth and Follower has 30 teeth. Movement ratio is
A.	0.6
B.	1.67
C.	20
D.	80
Answer» B. 1.67

Discussion

11.	A pair of spur gears consists of a 20 teeth pinion meshing with a 120 teeth gear. The module is 4 mm. Calculate the centre distance (in mm).
A.	240
B.	280
C.	360
D.	480
Answer» C. 360

Discussion

12.	A fixed-gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by arms. The number of turns made by the smaller gear for one revolution of the arm about the centre of the bigger gear is
A.	2
B.	3
C.	4
D.	5
Answer» E.

Discussion

13.	Constant velocity ratio between two shafts can be obtained, if they are connected by
A.	V-belts and pulleys
B.	Sprocket and chains
C.	Gears
D.	Universal joint
Answer» D. Universal joint

Discussion

14.	In the case of an involute toothed gear, involute stars from
A.	Addendum circle
B.	Dedendum circle
C.	Pitch circle
D.	Base circle
Answer» E.

Discussion

15.	A gear having 100 teeth is fixed and another gear having 25 teeth revolves around it, the centre lines of both gears being joined by an arm. How many revolutions will be made by the gear of 25 teeth for one revolution of the arm?
A.	4
B.	3
C.	5
D.	6
Answer» D. 6

Discussion

16.	An imaginary circle on a gear which gives a rolling action, as same as the motion as the actual gear, is called:
A.	Pitch circle
B.	Clearance circle
C.	Addendum circle
D.	Dedendum circle
Answer» B. Clearance circle

Discussion

17.	Gear 2 rotates at 1200 rpm in counter-clockwise direction and engages with Gear 3 and Gear 4 are mounted on the same shaft. Gear 5 engages with Gear 4. The numbers of teeth on Gear 2, 3, 4 & 5 are 20, 40, 15 and 30, respectively. The angular speed of Gear 5 is
A.	300 rpm counterclockwise
B.	300 rpm clockwise
C.	4800 rpm counterclockwise
D.	4800 rpm clockwise
Answer» B. 300 rpm clockwise

Discussion

18.	In which of the following type of gear train the first gear and the last gear are co-axial
A.	Reverted gear train
B.	Simple gear train
C.	Compound gear train
D.	None of the above
Answer» B. Simple gear train

Discussion

19.	In a reverted gear train with four gears, two gears P and Q are meshing Q – R is a compound gear, while R and S are meshing. The modulus of P and R are 6 mm and 5 mm respectively. The numbers of teeth in P, Q and R are 24, 36 and 40 respectively. The number of teeth in gear S is:
A.	32
B.	38
C.	42
D.	28
Answer» B. 38

Discussion

20.	Number of pairs of teeth in contact is given by [where, ϕ = pressure angle]:
A.	(Arc of contact)/(Circular pitch)
B.	(Path of contact)/(Circular pitch)
C.	(Arc of contact)/(cos ϕ × Circular pitch)
D.	(Arch of contact × cos ϕ)/(Circular pitch)
Answer» B. (Path of contact)/(Circular pitch)

Discussion

21.	A frictionless gear train is shown in the figure. The leftmost 12-teeth gear is given a torque of 100 N-m. The output torque from the 60-teeth gear on the right in N-m is
A.	5
B.	20
C.	500
D.	2000
Answer» E.

Discussion

22.	In the gear train of 1 : 10 as shown in the figure the pinion transits 250 kW at 1800 rpm. What is the tangential load on the gear tooth
A.	221 kN
B.	22.1 kN
C.	25.1 kN
D.	251 kN
Answer» C. 25.1 kN

Discussion

23.	If the axes of the first and last wheels of a compound gear coincide, it is called
A.	Simple gear train
B.	Compound gear train
C.	Epicyclic gear train
D.	Reverted gear train
Answer» E.

Discussion

24.	In an involute gear, the base circle must be ____.
A.	At root circle
B.	Under root circle
C.	Above root circle
D.	Under pitch circle
Answer» C. Above root circle

Discussion

25.	A power transmission mechanism consists of a belt drive and a gear train as shown in the figure.Diameters of pulleys of belt drive and number of teeth (T) on the gears 2 to 7 are indicated in the figure. The speed and direction of rotation of gear 7, respectively, are
A.	255.68 rpm; anticlockwise
B.	255.68 rpm; clockwise
C.	575.28 rpm; anticlockwise
D.	575.28 rpm; clockwise
Answer» C. 575.28 rpm; anticlockwise

Discussion

26.	Consider two shafts connected with two gears as per the following options:1. One on each shaft2. Through an intermediate gear mounted on an intermediate shaft, and every shaft having one gear only3. Through an intermediate gear mounted on an intermediate shaft, with the intermediate shaft having two gears, whereas the other shafts have one gear eachWhich of the above represent(s) a simple gear train?
A.	1 only
B.	1 and 2 only
C.	2 and 3 only
D.	1, 2 and 3
Answer» C. 2 and 3 only

Discussion

27.	A gear having 100 teeth is fixed and another gear having 25 teeth revolves around it, the centre lines of both gears being joined by an arm. How many revolution will be made by gear of 25 teeth for one revolution of arm:
A.	4
B.	3
C.	5
D.	6
Answer» D. 6

Discussion

28.	An epicyclic gear train is shown in the figure below. The number of teeth on the gears A, B and D are 20, 30 and 20, respectively. Gear C has 80 teeth on the inner surface and 100 teeth on the outer surface. If the carrier arm AB is fixed and the sun gear A rotates at 300 rpm in the clockwise direction, then the rpm of D in the clockwise direction is
A.	240
B.	-240
C.	375
D.	-375
Answer» D. -375

Discussion

29.	A fixed gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by an arm. The number of turns made by the smaller gear for one revolution of arm about the center of the bigger gear is
A.	2
B.	3
C.	4
D.	5
Answer» E.

Discussion

30.	An involute profile is used in
A.	pulleys
B.	cams
C.	chains
D.	gears
Answer» E.

Discussion

31.	An epicyclic gear train is shown schematically in the adjacent figure. The sun gear 2 on the input shaft is a 20 teeth external gear. The planet gear 3 is a 40 teeth external gear. The ring gear 5 is a 100 teeth internal gear. The ring gear 5 is fixed and the gear 2 is rotating at 60 rpm ccw (ccw = counter – clockwise and cw = clockwise) The arm 4 attached to the output shaft will rotate at
A.	10 rpm ccw
B.	10 rpm cw
C.	12 rpm cw
D.	12 rpm ccw
Answer» B. 10 rpm cw

Discussion

32.	In a pair of spur gear with external involute profile, the interference of tooth can be minimized by,
A.	Decreasing centre distance between gear pair
B.	Decreasing module
C.	Decreasing pressure angle
D.	Increasing number of gear teeth
Answer» E.

Discussion

33.	A gear train is made up of five spur gears as shown in the figure. Gear 2 is driver and gear 6 is driven member. N2, N3, N4, N5 and N6 represent number of teeth on gears 2, 3, 5 and 6 respectively. The gear(s) which act(s) as idler(s) is/are
A.	only 3
B.	only 4
C.	only 5
D.	Both 3 and 5
Answer» D. Both 3 and 5

Discussion

34.	Lewis equation in spur gear design is applied to
A.	Stronger of the pinion or gear
B.	Weaker of the pinion or gear
C.	Pinion
D.	Gear
Answer» C. Pinion

Discussion

35.	A pinion rotates at 1200 rpm and transmits a torque of 20 Nm. This pinion of 40 teeth mesh with the other spur gear having 60 teeth. The torque transmitted by the gear is:
A.	15 Nm
B.	30 Nm
C.	20 Nm
D.	40 Nm
Answer» C. 20 Nm

Discussion

36.	In case of Co-axial shifting, which of the following gear train is used?
A.	Reverted gear train
B.	Simple gear train
C.	Compound gear train
D.	Parallel gear train
Answer» B. Simple gear train

Discussion

37.	In the gear shown, gear 3 is carried on arm 5. Gear 3 meshes with gear 2 and gear 4. The number of teeth on gear 2, 3, and 4 are 60, 20, and 100, respectively. If gear 2 is fixed and gear 4 rotates with an angular velocity of 100 rpm in the counter-clockwise direction, the angular speed of arm 5 (in rpm) is
A.	166.7 counter-clockwise
B.	166.7 clockwise
C.	62.5 counter-clockwise
D.	62.5 clockwise
Answer» D. 62.5 clockwise

Discussion

38.	In a Gear Train of n wheels, the speed ratio is defined as
A.	\(\frac{{\mathop N\nolimits_1 }}{{\mathop N\nolimits_n }}\)
B.	\(\frac{{\mathop N\nolimits_n }}{{\mathop N\nolimits_1 }}\)
C.	\(\frac{{\mathop T\nolimits_1 }}{{\mathop T\nolimits_n }}\)
D.	\(\frac{{\mathop \omega\nolimits_n }}{{\mathop \omega\nolimits_1 }}\)
Answer» B. \(\frac{{\mathop N\nolimits_n }}{{\mathop N\nolimits_1 }}\)

Discussion

39.	A compound gear train with gears P, Q, R and S has number of teeth 20, 40, 15 and 20, respectively. Gears Q and R are mounted on the same shaft as shown in the figure below. The diameter of the gear Q is twice that of the gear R. If the module of the gear R is 2 mm, the center distance in mm between gears P and S is
A.	40
B.	80
C.	120
D.	160
Answer» C. 120

Discussion

40.	How the normal pitch (PN) and axial pitch (PC) related to a helical gear with helix angle α?
A.	PC = PN.cos α
B.	PC = PN / cos α
C.	PN = PC.sin α
D.	PN = PC / sin α
Answer» C. PN = PC.sin α

Discussion

41.	Differential gear is used in an automobile to
A.	transmit power from the engine to driving wheels.
B.	multiply the available engine torque
C.	enable the vehicle to negotiate the curves properly
D.	serves all the three functions as mentioned in 1), 2) and 3) above.
Answer» D. serves all the three functions as mentioned in 1), 2) and 3) above.

Discussion

42.	Planetary gear is in contact with the fixed gear as showing in the figure. The number of rotations made by the planetary gear for one rotation of the arm is
A.	3
B.	4
C.	1
D.	1/3
Answer» C. 1

Discussion

43.	If pitch diameter is 200 mm and number of teeth are 20 then circular pitch of the gear will be:
A.	31.4 mm
B.	314 mm
C.	0.314 mm
D.	3.14 mm
Answer» B. 314 mm

Discussion

44.	In a gear train where the axes of gears have motion are called:
A.	Reverted gcar train
B.	Epicyclic gear train
C.	Compound gear train
D.	Bevel wheel gear train
Answer» C. Compound gear train

Discussion

45.	A gearbox using an epicyclic gear train is used to supply 100 kW power to a machine. The input speed of supply gear shaft is 100 rad/s. The speed of output shaft of a gear box is 10 rad/s in opposite sense of supply speed. The holding torque on the fixed gear of the train is:
A.	9 kNm
B.	25 kNm
C.	5 kNm
D.	18 kNm
Answer» B. 25 kNm

Discussion

46.	A 20-tooth pinion meshes with a 63-tooth gear. The gear ratio is
A.	83.5
B.	43.5
C.	0.6
D.	3.15
Answer» E.

Discussion

47.	Power transmitted (Watts) by spur gear may be given as [Ft = tangential component of force (N), Fr = radial component of force (N), n = rotational speed (rpm), and d = pitch diameter (m)]
A.	\(\frac{{\pi dn{F_t}}}{{60}}\)
B.	\(\frac{{\pi dn{F_r}}}{{60}}\)
C.	\({\left( {\frac{{\pi dn}}{{60}}} \right)^2}{F_t}\)
D.	\({\left( {\frac{{\pi dn}}{{60}}} \right)^2}{F_r}\)
Answer» B. \(\frac{{\pi dn{F_r}}}{{60}}\)

Discussion

48.	A planetary gear train is gear train having
A.	A relative motion of axes and the axis of at least one of the gears also moves relative to the frame
B.	No relative motion of axes and no relative motion of axes with respect to the frame
C.	no relative motion of axes and the axis of at least one of the gears also moves relative to the frame
D.	a relative motion of axes and none of the axes of gears has relative motion with the frame
Answer» B. No relative motion of axes and no relative motion of axes with respect to the frame

Discussion

49.	Module of a gear is
A.	D/T
B.	T/D
C.	2D/T
D.	2T/D
Answer» B. T/D

Discussion

50.	If D is pitch circle diameter and T is the number of teeth then its circular pitch is
A.	\(\frac{{\pi T}}{D}\)
B.	\(\frac{{\pi D}}{T}\)
C.	D/T
D.	T/D
Answer» C. D/T

Discussion

Explore topic-wise MCQs in Machine Kinematics.

In a simple gear train, if the number of idle gears is odd, then the motion of driven gear will

The circular pitch of a gear is given by

The gear used to convert rotary motion into translating motion is

For the epicyclic gear arrangement shown in the figure, ω2 = 100 rad/s clockwise (CW) and ωarm = 80 rad/s counter clockwise (CCW). The angular velocity ω5 (in rad/s) is

In a simple gear train, 1st gear (Driver) has 40 number of teeth, 2nd gear has 20 number of teeth and last gear has 80 number of teeth. The train value of the gear train is -

For ω1 = 60 rpm clockwise (cw) when looked from the left, what is the angular velocity of the carrier and its direction so that Gear 4 rotates in counterclockwise (ccw) direction at twice the angular velocity of Gear 1 when looked from the left

In gears, interference takes place when _____.

In a reverted gear train, the axes of the first and last gear are:

In a compound gear train, gear F rotates in clockwise direction with 200 rpm. Find the rpm and direction of gear A. TA = 20, TB = 80, TC = 25, TD = 50, TE = 20, TF = 50

In a simple Gear Train, driver has 50 teeth and Follower has 30 teeth. Movement ratio is

A pair of spur gears consists of a 20 teeth pinion meshing with a 120 teeth gear. The module is 4 mm. Calculate the centre distance (in mm).

A fixed-gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by arms. The number of turns made by the smaller gear for one revolution of the arm about the centre of the bigger gear is

Constant velocity ratio between two shafts can be obtained, if they are connected by

In the case of an involute toothed gear, involute stars from

A gear having 100 teeth is fixed and another gear having 25 teeth revolves around it, the centre lines of both gears being joined by an arm. How many revolutions will be made by the gear of 25 teeth for one revolution of the arm?

An imaginary circle on a gear which gives a rolling action, as same as the motion as the actual gear, is called:

Gear 2 rotates at 1200 rpm in counter-clockwise direction and engages with Gear 3 and Gear 4 are mounted on the same shaft. Gear 5 engages with Gear 4. The numbers of teeth on Gear 2, 3, 4 & 5 are 20, 40, 15 and 30, respectively. The angular speed of Gear 5 is

In which of the following type of gear train the first gear and the last gear are co-axial

In a reverted gear train with four gears, two gears P and Q are meshing Q – R is a compound gear, while R and S are meshing. The modulus of P and R are 6 mm and 5 mm respectively. The numbers of teeth in P, Q and R are 24, 36 and 40 respectively. The number of teeth in gear S is:

Number of pairs of teeth in contact is given by [where, ϕ = pressure angle]:

A frictionless gear train is shown in the figure. The leftmost 12-teeth gear is given a torque of 100 N-m. The output torque from the 60-teeth gear on the right in N-m is

In the gear train of 1 : 10 as shown in the figure the pinion transits 250 kW at 1800 rpm. What is the tangential load on the gear tooth

If the axes of the first and last wheels of a compound gear coincide, it is called

In an involute gear, the base circle must be ____.

A power transmission mechanism consists of a belt drive and a gear train as shown in the figure.Diameters of pulleys of belt drive and number of teeth (T) on the gears 2 to 7 are indicated in the figure. The speed and direction of rotation of gear 7, respectively, are

A gear having 100 teeth is fixed and another gear having 25 teeth revolves around it, the centre lines of both gears being joined by an arm. How many revolution will be made by gear of 25 teeth for one revolution of arm:

A fixed gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by an arm. The number of turns made by the smaller gear for one revolution of arm about the center of the bigger gear is

An involute profile is used in

In a pair of spur gear with external involute profile, the interference of tooth can be minimized by,

A gear train is made up of five spur gears as shown in the figure. Gear 2 is driver and gear 6 is driven member. N2, N3, N4, N5 and N6 represent number of teeth on gears 2, 3, 5 and 6 respectively. The gear(s) which act(s) as idler(s) is/are

Lewis equation in spur gear design is applied to

A pinion rotates at 1200 rpm and transmits a torque of 20 Nm. This pinion of 40 teeth mesh with the other spur gear having 60 teeth. The torque transmitted by the gear is:

In case of Co-axial shifting, which of the following gear train is used?

In a Gear Train of n wheels, the speed ratio is defined as

How the normal pitch (PN) and axial pitch (PC) related to a helical gear with helix angle α?

Differential gear is used in an automobile to

Planetary gear is in contact with the fixed gear as showing in the figure. The number of rotations made by the planetary gear for one rotation of the arm is

If pitch diameter is 200 mm and number of teeth are 20 then circular pitch of the gear will be:

In a gear train where the axes of gears have motion are called:

A gearbox using an epicyclic gear train is used to supply 100 kW power to a machine. The input speed of supply gear shaft is 100 rad/s. The speed of output shaft of a gear box is 10 rad/s in opposite sense of supply speed. The holding torque on the fixed gear of the train is:

A 20-tooth pinion meshes with a 63-tooth gear. The gear ratio is

Power transmitted (Watts) by spur gear may be given as [Ft = tangential component of force (N), Fr = radial component of force (N), n = rotational speed (rpm), and d = pitch diameter (m)]

A planetary gear train is gear train having

Module of a gear is

If D is pitch circle diameter and T is the number of teeth then its circular pitch is