Cam and Gear
Exam Duration: 45 Mins Total Questions : 25
The size of a cam depends upon
- (a)
base circle
- (b)
pitch circle
- (c)
pitch curve
- (d)
prime circle
A circle drawn with centre as the cam centre and radius equal to the distance between the cam centre and the point on the pitch curve at which the pressure angle is maximum, is called
- (a)
prime circle
- (b)
pitch circle
- (c)
base circle
- (d)
None of these
Offet is provided to cam follower mechanism to
- (a)
minimise the side thrust
- (b)
avoid jerk
- (c)
accelerate
- (d)
None of these
The angle between the direction of the follower motion and a normal to the pitch curve is called
- (a)
pitch angle
- (b)
prime angle
- (c)
pressure angle
- (d)
base angle
An imaginary circle which by pure rolling action, gives the same motion as the actual gear is called
- (a)
addendum circle
- (b)
pitch circle
- (c)
clearance circle
- (d)
dedendum circle
In a gear train, when the axes of the shafts over which the gears are mounted, move relative to a fixed axis, is called
- (a)
simple gear train
- (b)
epicyclic gear train
- (c)
reverted gear train
- (d)
compound gear train
In a simple gear train, if the number of idle gears is odd, then the motion of driven gear will
- (a)
be same as that of driving gear
- (b)
be opposite as that of driving gear
- (c)
depend upon profile of teeth
- (d)
None of the above
Consider a cam profile in which the follower moves with uniform acceleration and deceleration. During returning acceleration is half the deceleration.
If angle of descent = 120°, then angle of acceleration and deceleration is
- (a)
40°, 60°
- (b)
40°, 80°
- (c)
0°, 120°
- (d)
60°, 60°
Consider a cam profile in which the follower moves with uniform acceleration and deceleration. During returning acceleration is half the deceleration.
If angle of ascent is 100°, then angle of dwell is
- (a)
100°
- (b)
200°
- (c)
140°
- (d)
150°
Consider a cam rotating with uniform angular velocity 50 rad/s. Follower also moves with uniform velocity. Lift of follower is 100 mm.
If angle of ascent, descent and dwell all are same then angle of ascent is
- (a)
90°
- (b)
180°
- (c)
60°
- (d)
120°
Consider a cam rotating with uniform angular velocity 50 rad/s. Follower also moves with uniform velocity. Lift of follower is 100 mm.
Velocity of follower at mid stroke is
- (a)
2.5 M/s2
- (b)
1.2 M/s2
- (c)
2.3 M/s2
- (d)
4.0 M/s2
Consider a cam rotating with uniform angular velocity 50 rad/s. Follower also moves with uniform velocity. Lift of follower is 100 mm.
Acceleration of follower at 60°
- (a)
4 m/s2
- (b)
6 m/s2
- (c)
2 m/s2
- (d)
zero
Consider a cam follower in which cam is rotating with uniform angular velocity \(\omega \) rad/s and follower moves in SHM. If displacement of follower is given as
\(y=\frac { s }{ 2 } \left( 1-cos\frac { \pi }{ \theta _{ 0 } } \theta \right) \)
where, \(\theta\) is angle turned by cam in time T, then
Maximum velocity of follower is
- (a)
zero
- (b)
\(\frac { \pi }{ { \theta }_{ 0 } } s\omega \)
- (c)
\(\frac { \pi }{ { \theta }_{ 0 } } \frac { s }{ 2 } \omega \)
- (d)
\(\frac { \pi }{ { \theta }_{ 0 } } s{ \omega }^{ 2 }\)
Consider a cam follower in which cam is rotating with uniform angular velocity \(\omega \) rad/s and follower moves in SHM. If displacement of follower is given as
\(y=\frac { s }{ 2 } \left( 1-cos\frac { \pi }{ \theta _{ 0 } } \theta \right) \)
where, \(\theta\) is angle turned by cam in time T, then
Maximum acceleration of follower is
- (a)
\(\pm \frac { { \pi }^{ 2 }s }{ { \theta }_{ 0 }^{ 2 } } \frac { s }{ 2 } { \omega }^{ 2 }\)
- (b)
zero
- (c)
\(\pm \frac { { \pi }^{ 2 } }{ { \theta }_{ 0 }^{ 2 } } { s\omega }^{ 2 }\)
- (d)
None of these
Consider a cam follower in which cam is rotating with uniform angular velocity \(\omega \) rad /s and follower moves in SHM. If displacement of follower is given as
\(y=\frac { s }{ 2 } \left( 1-cos\frac { \pi }{ \theta _{ 0 } } \theta \right) \)
where, \(\theta\) is angle turned by cam in time T, then
Jerk at end of stroke is
- (a)
zero
- (b)
\(\frac { { \pi }^{ 3 } }{ { \theta }_{ 0 }^{ 3 } } \frac { s }{ 2 } { \omega }^{ 3 }\)
- (c)
\(\frac { { \pi }^{ 3 } }{ { \theta }_{ 0 }^{ 3 } } s{ \omega }^{ 3 }\)
- (d)
None of these
A wheel and pinion having different modules are meshing with each other. If diameters of wheel and pinion are 100 mm and 20 mm respectively, then number of teeth on pinion is (given, teeth on wheel are 40)
- (a)
8
- (b)
16
- (c)
12
- (d)
Data is insufficient
Minimum number of teeth on pinion to avoid interference with rack is (given, addendum coefficient of rack = 1.8 and pressure angle of pinion is 20°)
- (a)
25
- (b)
35
- (c)
31
- (d)
Data is insufficient
If two gears A and B are meshing with each other such that A rotates with 100 rpm. If mA = 2 mm, mB = 4 mm and tA = 50, tB = 30, then revolution of gear B is
- (a)
60 rpm
- (b)
100 rpm
- (c)
92 rpm
- (d)
84 rpm
Consider two pinon gears meshing with each other. If vs and vr are sliding and rolling velocity at pitch point then
- (a)
vs = vr
- (b)
vs = 0
- (c)
v = 0r
- (d)
Data is insufficient
In which type of profile of gear, there occurs interference?
- (a)
Involute profile
- (b)
Cycloidal profile
- (c)
Both (a) and (b)
- (d)
None of these
In the given figure, four gears are meshing with each other. Given, t1 = 20, t2 = 40, t3 = 10, N1 = 100 rpm. Each gear has same module.
Number of teeth on gear 4 is
- (a)
100
- (b)
60
- (c)
60
- (d)
50
In the given figure, four gears are meshing with each other. Given, t1 = 20, t2 = 40, t3 = 10, N1 = 100 rpm. Each gear has same module.
Speed of gear (4 in rpm) is
- (a)
70
- (b)
40
- (c)
10
- (d)
50
An epicyclic gear train is shown in figure. It has fix annular wheel and an arm L.
Given, tA = 150, Narm = 100 rpm (clockwise) tB = 25, tD = 40. Determine
Number of teeth on C is
- (a)
40
- (b)
30
- (c)
50
- (d)
60
An epicyclic gear train is shown in figure . It has fix annular wheel and an arm L.
Given, tA = 150, Narm = 100 rpm (clockwise) tB = 25, tD = 40. Determine
Speed of Gear C (rpm)
- (a)
600
- (b)
100
- (c)
1000
- (d)
400
Which one of the following is not applicable to involute profile?
- (a)
The angular velocity ratio when two involutes are in mesh, is inversely proportional to the size of the base circle
- (b)
Pitch diameters of meshing involutes are inversely proportional to their base circle diameters
- (c)
No involute has a pressure angle until it is brought in contact with other meshing involute
- (d)
Involute is the only form that is not sensitive to centre distance of their base circle
1654060945.png)
1654060942.png)
1653987551.png)
1653987086.png)
1582095229.jpg)
