Question 9 to 16.
9. The moment of a force about a point is defined as the: (a) product of force and its distance from fulcrurn (b) algebraic sum of forces acting at that point (c) product of force and perpendicular
distance of its line of action from the point (d) product of force and any convenient distance.
10. A steel wire of length 2m and cross-sectional
area0.8 × 106m² has a young modulus of 2\times 1011 pa the upper end of the wire is fixed and a load
of 4N is tied at the other end. The extension in the
wire (a) 0.02mm (b)0.05mm (c)0.50mm (d) 1.00mm
is
11. Given that A=4i+5j+6k and 2j+3k. Find AXB B=i+\_
(a) 3i+6j-3k (b) 3i-6j+3k (c) -3i+ 6j+3k(d)3i+6j+3k .
12. A box is pulled a distance s along a smooth horizontal floor by a force of inagnitude F. inclined at an angle to the horizontal. The work done is
(a) F.s~cos~\theta (b) Fscosece (c) Fs sece (d) Fs sing
13. Two equal velocities have their resultant equal to either. What is the inclination between them? (a)60^{\circ}(b)90^{\circ} (c) 120^{\circ} (d) 190^{\circ}
14. The potential energy in an elastic string of force constant k which has been extended by x metres is expressed as (a) \frac{1}{2}kx^{2} (b) kx^{2}(c ) kx (d)
\frac{1}{2}kx
15. The point beyond which stretched spring does not return to its original length is called the (a) breaking point (b) spring constant (c) elastic limit (d) clasticity point.
16. The compressibility of a material
(a) the product of volume and its pressure (b) the fractional change in volume per unit pressure (c)