ESE ME Theory of Machines & Vibrations : National Champion Test for ESE & GATE ME Exams

Question 1

The below figure shown the required velocity profile for a follower of a cam during its rise. If the nature of displacement recommended for the follower is

Question 2

Gearing contact is which one of the following?

Question 3

Consider the following statements:
1) Lower pairs are more resistant than higher pairs in a plane mechanism.
2) In a 4-bar mechanism (with 4 turning pairs), when the link opposite to the shortest link is fixed, a double rocker mechanism results.
Which of these statements is/are correct?

Question 4

In a watt governor the weight of the ball is 50 N and the friction at the sleeve is 10 N. The coefficient of detention would be:

Question 5

Match List-I (Type of Gears) with List-II (characteristics) and select the correct answer using the code given below the lists:
List-I
A) Helical gearing
B) Herringbone gearing
C) Worm gearing
D) Hypoid gearing
List-II
1) Zero axial thrust
2) Non-inter-changeable
3) Skew shafts
4) Parallel shafts

Question 6

Two spur gears of

full depth involute system are transmitting motion with a gear ratio of 2. The ration of the base circle radil of the gears would be:

Question 7

consider the following statements:
In the case of involute gears in contact
1) The motion is one of pure rolling
2) Pressure angle does not change during contact
3) Velocity ratio does not change
4) Output torque of the driven gear changes
Which of the above statements are correct?

Question 8

Consider the following statements
The transmission of motion from a pinion to a meshing gear of involute profile is a case of
1) Pure rolling
2) Sliding with constant velocity of sliding
3) Sliding with time varying velocity of sliding
4) Rolling with some amount of sliding
Which of these statements are correct?

Question 9

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

Question 10

The flywheel of a machine having weight of 4500N and radius of gyration of 2 m has cyclic fluctuation of speed from 125 r.p.m. to 120 r.p.m. Assuming

, the maximum fluctuation of energy is

Question 11

Purpose of using differential gear in automobile is to _______.

Question 12

The following are the data for two crossed helical gears used for speed reduction:
Gear I: Pitch circle diameter in the plane of rotation 80 mm and helix angle 30 °
Gear II: Pitch circle diameter in the plane of rotation 120 mm and helix angle 22.5 °
If the input speed is 1440 rpm, the output speed in rpm is

Question 13

The speed of an engine varies from 210 rad/s to 190 rad/s. During a cycle the change in kinetic energy is found to be 400 Nm. The inertia of the flywheel in kgm² is

Question 14

Which one of the following is the correct arrangement of Watt Governor?

Question 15

Which among the following are the examples of free vibrations?

Question 16

In a spring-mass system, the mass is m and the spring constant is k. The critical damping coefficient of the system is 0.1 kg/s. In another spring-mass system, the mass is 2m and the spring constant is 8k. The critical damping coefficient (in kg/s) of this system is _________

Question 17

A mass-spring-dashpot system with mass m = 10 kg, spring constant k = 6250 N/m is excited by a harmonic excitation of 10cos(25t) N. At the steady state, the vibration amplitude of the mass is 40 mm. The damping coefficient (c, in N.s/m) of the dashpot is ______

Question 18

In a flywheel, the arms carry full torque load due when the energy input to shaft is cut off. If the arm is cantilever fixed at hub which carries load at rim end, then what will be the expression for bending stress when major axis of arms are parallel to tangential force F acting on flywheel.

Question 19

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

Question 20

Which process according to refrigeration cycle is incorrect?
Match the item in columns I and II
Column I
I. Toothed Wheel
II. Assembly of bodies
III. Structural element
IV. Tooth

Column II
1) Cam
2) Beam
3) Linkage
4) Gear

Question 21

The crankshaft of a reciprocating engine having a 20 cm crank and 100 cm connecting rod rotates at 210 r.p.m. when the crank angle is 45^o, the velocity of piston in nearly

Question 22

in the case of involute system of gears, if the centre distance is changed

Question 23

pressure angle of involute gears does not exceed

, since

Question 24

In a Hartnell governor, the mass of each ball is 2.5kg, maximum and minimum centrifugal forces on the balls are 2000 N and 100 N corresponding to radii 20cm and 15 cm respectively. Lengths of vertical and horizontal arms of the bell-crank levers are the same, then what is the spring stiffness in N/cm?

Question 25

A machine is coupled to a power source. The machine requires constant torque but torque supplied by the power source is (800+200sinθ) N-m. Mass moment of inertia of the flywheel is 400 kg-m². What is the maximum angular acceleration of the flywheel and at what position does it occur?

Question 26

In a flywheel, the safe stress is

and the density is

Then what is the maximum peripheral velocity

Question 27

which of the following are responsible for occurrence of critical or whirling speed of shaft?
1) Eccentric mounting of the rotor
2) Non-uniform distribution of rotor material
3) Bending of shaft due to the weight of the rotor and the shaft itself
4) Environmental effect such as effect of moisture and temperature
Select the correct answer using the code given below:

Question 28

Which one of the following is the correct statement?
In meshing gears with involute gear teeth, the contact begins at the intersection of the

Question 29

For a governor running at constant speed, what is the value of the force acting on the sleeve___?

Question 30

The sensitiveness of a governor is defined as