Applied Mechanics 4

Objective Questions and Answers of Civil Engineering: Applied Mechanics 4

Subject: Applied Mechanics 4

Part 4: Objective questions and answers of Applied Mechanics


Q1. A circular disc rotates at n rpm. The angular velocity of a circular ring of same mass and radius as the disc and to have the same angular momentum is

a) N rpm

b) N/2 rpm

c) N/4 rpm

d) 2n rpm


Q2. When a circular wheel rolls on a straight track, then the shape of body centrode and space centrode respectively are

a) Straight line and parabola

b) Straight line and circle

c) Circle and straight line

d) Circle and parabola


Q3. Instantaneous center is at infinity when the angular velocity is

a) Constant

b) Zero

c) Maximum

d) Minimum


Q4. A 2 m long ladder rests against a wall and makes an angle of 30° with the horizontal floor. Where will be the instantaneous center of rotation when the ladder starts slipping?

I) 1.0 in from the wall

Ii) 1.732 m from the wall

Iii) 1.0 m above the floor

Iv) 1.732 m above the floor the correct answer is

a) (i) and (iii)

b) (i) and (iv)

c) (ii) and (iii)

d) (ii) and (iv)


Q5. The angle of projection at which the horizontal range and maximum height of a projectile are equal to

a) 36°

b) 45°

c) 56°

d) 76°


Q6. A stone is thrown vertically upwards with a vertical velocity of 49 m/sec. It returns to the ground in

a) 5 sec

b) 8 sec

c) 10 sec

d) 20 sec


Q7. If the direction of projection bisects the angle between the vertical and the inclined plane, then the range of projectile on the inclined plane is

a) Zero

b) Maximum

c) Minimum

d) Unpredictable


Q8. The angle of projection at which the horizontal range and maximum height of a projectile are equal to

a) 45°

b) Tan-1 (2)

c) Tan-‘ (4)

d) Tan”1 (1/4)


Q9. A stone is thrown up a slope of inclination 60° to the horizontal. At what angle to the slope must the stone be thrown so as to land as far as possible from the point of projection?

a) 15°

b) 30°

c) 45°

d) 75°


Q10. If a is the amplitude of particle executing simple harmonic motion, then the total energy e of the particle is

a) Proportional to a

b) Proportional to a2

c) Proportional to 1/a^2

d) Independent of a


Q11. A particle of mass 2 kg executes simple harmonic motion of frequency 6/71 hz and amplitude 0.25 m. Its maximum kinetic energy is

a) 4.5 j

b) 9.0 j

c) 12.0 j

d) 18.0 j


Q12. It is observed that in a certain sinusoidal oscillation, the amplitude is linearly dependent on the frequency f. If the maximum velocity during the oscillation is v, then v must be proportional to

a) F

b) 1/f

c) 1/f2

d) F2


Q13. If the kinetic energy and potential energy of a simple harmonic oscillator of amplitude a are both equal to half the total energy, then the displacement is equal to

a) A

b) A/2

c) A/v2

d) Av2


Q14. A simple pendulum of length / has an energy e, when its amplitude is a. If the length of pendulum is doubled, the energy will be

a) E

b) E/2

c) 2e

d) 4e


Q15. Time period and length of a second’s pendulum respectively are

a) 1 sec and 99.4 cm

b) 1 sec and 92.7 cm

c) 2 sec and 99.4 cm

d) 2 sec and 92.7 cm


Q16. One end of an elastic string of natural length / and modulus x is kept fixed while to the other end is attached a particle of mass m which is hanging freely under gravity. The particle is pulled down vertically through a distance x, held at rest and then released. The motion is

a) A simple harmonic motion

b) A rectilinear motion with constant speed

c) A damped oscillatory motion

d) None of the above


Q17. The potential energy of a particle falling through a straight shaft drilled through the earth (assumed homogenous and spherical) is proportional to

a) Log r

b) R

c) R2

d) 1/r

Where r is the distance of the particle from center of the earth


Q18. One newton is equivalent to

a) 10^5 dyne

b) 10^6 dyne.

c) 10^7 dyne

d) 98^1 dyne


Q19. A quantity whose dimensions are m2l2 t3 could be the product of

a) Force and pressure

b) Mass and power

c) Energy and velocity

d) Force and velocity


Q20. If y is force and x is velocity, then dimensions of —=r are dx2

a) M’^t’

b) M’l-‘t0

c) M’l-‘t1

d) M2l’t3


Part 4: Objective questions and answers of Applied Mechanics


Q1. Answer b


Q2. Answer c


Q3. Answer b


Q4. Answer d


Q5. Answer d


Q6. Answer c


Q7. Answer b


Q8. Answer c


Q9. Answer a


Q10. Answer b


Q11. Answer b


Q12. Answer d


Q13. Answer c


Q14. Answer b


Q15. Answer c


Q16. Answer a


Q17. Answer c


Q18. Answer a


Q19. Answer b


Q20. Answer b