Gears with involute tooth profile transmit constant velocity ratios between shafts connected by them.

Consider the following statements: 1. In spur gears, the contact occurs abruptly on a line parallel to the axis, and the disengagement too is abrupt. 2. In helical gears, both loading and unloading are gradual, and therefore, these happen more smoothly and less noisily 3. When two gears mesh, any arbitrary shape of the tooth can be chosen for the profile of the teeth of any one of the two gears, and the profile for the other shall be obtained by applying the law of gearing. Which of the above statements are correct?

A

1 and 2 only

B

1 and 3 only

C

2 and 3 only

D

1, 2 and 3

Tapered involute gears which can couple intersecting shafts, skew shafts, and parallel shafts are known as

A

bevel gears

B

beveloid gears

C

mitre gears

D

none of the mentioned

Consider the following statements regarding gear tooth designing for gear drive: 1. Tooth profiles not designed as per ‘law of gearing’ will cause vibration and impact problems even at low speed. 2. As the gears go through their mesh, the pitch point must remain stationary on the line of centres. 3. In a correctly designed tooth profile, the line of action of successive instantaneous points of contact will pass through the stationary pitch point. Which of the above statements are correct?

A

1, 2 and 3

B

1 and 2 only

C

1 and 3 only

D

2 and 3 only

Statement (I): Two non-intersecting and non-parallel, i.e., non-coplanar, shafts connected by gears are called skew-bevel gears or spiral gears, and this type of gearing has a line contact the rotation of which about the axes generates the two hyperboloid pitch surfaces. Statement (II): A hyperboloid is a 3D surface formed by revolving a straight line about an axis (not in the same plane), such that every point on the line remains at a constant distance from the axis.

A

Both Statement I) and Statement II) are individually true and Statement II) is the correct explanation of Statement I)

B

Both Statement I) and Statement II) are individually true but Statement II) is not the correct explanation of Statement I)

C

Statement I) is true but Statement II) is false

D

Statement I) is false but Statement II) is true

Consider two shafts connected with two gears as per the following options: 1. One on each shaft 2. Through an intermediate gear mounted on an intermediate shaft, and every shaft having one gear only 3. Through an intermediate gear mounted on an intermediate shaft, with the intermediate shaft having two gears, whereas the other shafts have one gear each Which 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

Consider the following statements: 1. A stub tooth has a working depth larger than that of a full-depth tooth. 2. The path of contact for involute gears is an arc of a circle. Which of the statements given above is/are correct?

A

Only 1

B

Only 2

C

Both 1 and 2

D

Neither 1 nor 2

Hollow shafts can be made as strong as solid shafts by making the twisting moments of both the shafts same. Shafts made by __________ have residual stresses.

A

Forging

B

Cold rolling

C

Hot rolling

D

Casting

Statement I: Hooke’s joint connects two non-parallel non-intersecting shafts to transmit motion with a constant velocity ratio. Statement II: Hooke’s joint connects two shafts the axes of which do not remain in alignment while in motion.

A

Both Statement I) and Statement II) are individually true and Statement II) is the correct explanation of Statement I)

B

Both Statement I) and Statement II) are individually true but Statement II) is not the correct explanation of Statement I)

C

Statement I) is true but Statement II) is false

D

Statement I) is false but Statement II) is true

Which of the following statements are correct for mating gears with involute profiles? 1. The pressure angle, from the start of the engagement to the end of the engagement, remains constant. 2. The pressure angle is maximum at the beginning of the engagement, reduces to zero at pitch point, starts decreasing and again becomes maximum at the end of the engagement. 3. The face and flank of the teeth are generated by a single curve and the normal to this curve at any point is tangent to the base circle of the gear. 4. The centre distance for a pair of mating gears can be varied within limits without altering the velocity ratio. Select the correct answer using the code given below.

A

1, 3 and 4

B

1 and 3 only

C

2 and 4 only

D

2, 3 and 4

Which of the following statements are correct for mating gears with involute profiles? (i) The pressure angle, from the start of the engagement to the end of the engagement, remains constant. (ii) The pressure angle is maximum at the beginning of the engagement, reduces to zero at pitch point, starts decreasing and again becomes maximum at the end of the engagement. (iii) The face and flank of the teeth are generated by a single curve and the normal to this curve at any point is tangent to the base circle of the gear. (iv) The centre distance for a pair of mating gears can be varied within limits without altering the velocity ratio. Select the correct answer using the code given below.

A

1, 3 and 4

B

1 and 3 only

C

2 and 4 only

D

2,3 and 4

Gears with involute tooth profile transmit constant velocity ratios between shafts connected by them.

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