INTELLIGENT OBJECTIVE QUESTIONS IN MECHANICS

1) A cantilever beam of square cross-section (100 mm X 100 mm) and length 2 m carries a concentrated load of 5 kN at its free end. What is the maximum normal bending stress at its mid-length cross-section?

(a) 10 N/mm²
(b) 20 N/mm²
(c) 30 N/mm²
(d) 40 N/mm²

2) A hollow shaft of outside diameter 40 mm and inside diameter 20 mm is to replaced by a solid shaft of 30 mm diameter. If the maximum shear stresses induced in the two shafts are to be equal, what is the ratio of the maximum resistible torque in the hollow to that of solid shaft?

(a) 10/9
(b) 20/9
(c) 30/9
(d) 40/9

(3) A cannonball is fired from a tower 80 m above the ground with a horizontal velocity of 100 m/s. Determine the horizontal distance at which the ball will hit the ground. (take g=10 m/s²)

(a) 400 m,
(b) 280 m,
(c) 200 m,
(d) 100 m.

(4) Water drops from a tap at the rate of four droplets per second. Determine the vertical separation between two consecutive drops after the lower drop attained a velocity of 4 m/s. Take g=10 m/s².

(a) 0.49 m
(b) 0.31 m
(c) 0.50 m
(d) 0.30 m

MULTIPLE CHOICE QUESTIONS: ENGINEERING MECHANICS

Choose the correct answer:

Q.1) In a simply supported beam of length L, a UDL of w kN/m acts on the entire span of the beam. The maximum bending moment will be
a. (w.L²)/8 b. (w.L³)/8 c. (w.L²)/4 d. (w.L³)/4

Q.2) If two forces are acting on a particle and the particle is in a stable equilibrium, then the forces are,
a. equal to each other
b. equal but opposite in direction
c. they are unequal but the direction is same.
d. none of the above.

Q.3) The example of Statically indeterminate structures are,
a. continuous beam,
b. cantilever beam,
c. over-hanging beam,
d. both cantilever and fixed beam.

Q.4) A redundant truss is defined by the truss satisfying the equation,
a. m = 2j - 3,
b. m < 2j + 3,
c. m > 2j - 3,
d. m > 2j + 3

Q.5) The property of a material to withstand a sudden impact or shock is called,
a. hardness b. ductility,
c. toughness, d. elasticity
of the material.

Q.6) The stress genarated by a dynamic loading is approximately _____ times of the stress developed by the gradually applying the same load.

Q.7) The ratio between the volumetric stress to the volumetric strain is called as
a. young's modulus
b. modulus of elasticity
c. rigidity modulus,
d. bulk modulus.

Q.8) In a Cantilever beam, the maximum bending moment is induced at
a. at the free end
b. at the fixed end
c. at the mid span of the beam
d. none of the above.

Q.9) The forces which meet at a point are called
a. collinear forces
b. concurrent forces
c. coplanar forces
d. parallel forces.

Q.10) The coefficients of friction depends upon
a. nature of the surface
b. shape of the surface
c. area of the contact surface
d. weight of the body.

Q.11) The variation of shear force due to a triangular load on simply supported beam is
a. uniform b. linear
c. parabolic d. cubic.

Q.12) A body is on the point of sliding down an inclined plane under its own weight. If the inclination of the plane is 30 degree, then the coefficient of friction between the planes will be
a. (1/3)^½ b. 3^½ c. 1 d. 0