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