Workshop Instructor (Mechanic) 1

WORKSHOP INSTRUCTOR (MECHANIC) IN TECHNICAL EDUCATION DEPARTMENT              
(EXAMINATION HELD ON 08/05/2009)

1. A particle is acted up on by a force of constant magnitude which is always perpendicular to the velocity of the particle. The motion of the particle takes place in a plane. It follows that the particle has:

(A) motion in a circular path (B) constant velocity
(C) constant acceleration D) constant kinetic energy

Ans. (A) motion in a circular path

2. An artificial satellite stays in an orbit around the earth. This may be attributed to:

(A) upward pull of the satellite
(B) negligible earth’s gravitational field
(C) centripetal force provided by earth’s gravitational acceleration.
(D) equilibrium between forces of attraction due to earth and other planes

Ans. (B) negligible earth’s gravitational field

3. A solid sphere, a spherical shell, a ring and a disc have the same mass and the same radius. Which of the following cases have the highest moment of inertia?

(A) the solid sphere about one of its diameter
(B) the spherical shell about one of its diameter
(C) the ring about its axis perpendicular to the plane of the ring
(D) the disc about its axis perpendicular to the plane of the disc

Ans. (A) the solid sphere about one of its diameter

4. For the most brittle materials the ultimate strength in compression is much larger than the ultimate strength in tension. This is mainly due to:

(A) presence of microscopic cracks or cavities
(B) necking in tension compressive stress
(C) severity of tensile stress as compared to
(D) non-linearity of stress strains diagram

Ans. (A) presence of microscopic cracks or cavities

5. Brinell number of a metal or alloy is a measure of its:

(A) tensile strength
(B) toughness
(C) malleability
(D) hardness

Ans. (D) hardness