(a) What is the position of centre of gravity of a triangular lamina? (b) When this triangular lamina is suspended freely from any one vertex, what is the moment of force produced by its own weight in its rest position?

Clockwise moment produced by a force about a fulcrum is considered to be: (a) Positive (b) Negative (c) Zero (d) None of these

A metre scale of weight 50 gf can be balanced at 40 cm mark without any weight suspended on it. (a) If this ruler is cut at its centre then state which part [0 to 50 cm or 50 to 100 cm] of the ruler will weigh more than 25 gf. (b) What minimum weight placed on this metre ruler can balance this ruler when it is pivoted at its centre?

A non-uniform kite is hanging freely from the branch of a tree as shown. Study the figure and answer the following: (a) Fill in the blank. ............... [P, Q, R or S] is the most probable position of its centre of gravity. (b) Support your answer to (a) with a reason.

Fill in the blanks: (a) A stone tied to a string is rotated in a horizontal plane. The tension in the string provides the __________ force necessary for circular motion. (b) The work done by this force at any instant is __________.

A non-uniform beam of weight 120 N pivoted at one end is shown in the diagram below. Calculate the force F required to keep the beam in equilibrium.

State two factors on which the position of Center of Gravity of a body depends.

A door lock is opened by turning the lever (handle) of length 0.2 m. If the moment of force produced is 1 Nm, then the minimum force required is: (a) 5 N (b) 10 N (c) 20 N (d) 0.2 N

Which among the following is a vector quantity? (a) work (b) power (c) energy (d) moment of couple

A body is acted upon by two equal and opposite forces, that are NOT along the same straight line. The body will : (a) remain stationary (b) have only rotational motion (c) have only rectilinear motion (d) have both rectilinear and rotational motion

When a bell fixed on a cycle rings, then the energy conversion that takes place is: (a) gravitational potential energy to sound energy (b) kinetic energy to sound energy (c) sound energy to electrical energy (d) sound energy to mechanical energy

Complete the following by choosing the correct answers from the bracket: (a) In uniform circular motion the centrifugal force acts ............... [towards the centre/away from the centre/along the tangential direction]. (b) Refractive index of a medium is independent of ............... [temperature/angle of incidence/wavelength of light]. (c) Heat absorbed during change of phase depends on ............... [mass/change in temperature/specific heat capacity] of the substance. (d) Emf of a cell is ............... [greater than/less than/equal to] the terminal voltage when the cell is in open circuit. (e) In a step-up transformer the turns ratio is ............... [more than 1/less than 1/equal to 1]. (f) The nuclear radiation with lowest ionising power is ............... [α/β/γ].