Question

3 Which of the following is NOT correct?
Electric charge cannot be produced by frictional forces
Electric charge is conserved
Electric charges are integral multiple of the electronic charge
induced charges are the result of charge separation within a material

4 Which of the following is not true of an electrostatic force?
it acts along the line joining the point charges
it obeys an inverse square law
it is mutually attractive or repulsive
it is weaker than the gravitational attraction between the charged particles.

5 A tiny ball of mass 0.60 g is suspended from a rigid support with a piece of thread in a horizontal electric field of intensity 700 N/C. The ball is in equilibrium when the thread is inclined at an angle of
20o
to the vertical. What are the magnitude and sign of the charge on the ball? Take
g=9.8m/s2
−3.1×10−6C
3.2×10−6C
4.2×10−6C
−4.1×10−3