21. The angle which the normal reaction makes with the resultant reaction is called the angle of friction.
A. Agree
B. Disagree
22. Which of the following statement is correct?
A. The periodic time of a particle moving with simple harmonic motion is the time taken by a particle for one complete oscillation,
B. The periodic time of a particle moving with simple harmonic motion is directly proportional to its angular velocity.
C. The velocity of the particle moving with simple harmonic motion is zero at the mean position.
D. The acceleration of the particle moving with simple harmonic motion is maximum at the mean position.
23. The law of the machine is(where P = Effort applied to lift the load, m = A constant which is equal to the slope of the line, W = Load lifted, and C = Another constant which represents the machine friction.)
A. P = mW – C
B. P = m/W + C
C. P = mW + C
D. P = C – mW
24. In a framed structure, as shown in the below figure, the force in the member AB is __________ the force in member AC.
A. half
B. equal to
C. double
25. The velocity of a body on reaching the ground from a height h is
A. 2.√(gh)
B. √(gh)
C. √(2gh)
D. 2g.√h
26. The moment of the force P about O as shown in the below figure is
A. P x OA
B. P x OB
C. P x OC
D. P x AC
27. According to lami’s theorem
A. the three forces must be equal
B. the three forces must be at 120° to each other
C. the three forces must be in equilibrium
D. if the three forces acting at a point are in equilibrium, then each force is proportional to the sine of the angle between the other two
28. Moment of inertia of a hollow circular section, as shown in the below figure about an axis perpendicular to the section, is __________ than that about X–X axis.
A. two times
B. same
C. half
29. The amplitude is always __________ radius of the circle.
A. equal to
B. less than
C. greater than
30. When a body falls freely under gravitational force, it possesses __________ weight.
A. no
B. minimum
C. maximum