Answer:
5. Quadruple
Explanation:
The electrostatic force between two charged particles is given by:

where
k is the Coulomb's constant
q1, q2 are the two charges
r is the separation between the charges
If the distance between the charges is reduced to half,

So the new force will be

So, the force will quadruple.
Answer:
The correct answer is 231 Mpa i.e option a.
Explanation:
using the equation of torsion we Have

where,
= shear stress at a distance 'r' from the center
T = is the applied torque
= polar moment of inertia of the section
r = radial distance from the center
Thus we can see that if a point is located at center i.e r = 0 there will be no shearing stresses at the center due to torque.
We know that in case of a circular section the maximum shearing stresses due to a shear force occurs at the center and equals

Applying values we get

In your question where the ask is to calculate the charge that the small sphere carries which is the mass of it is 441g moving at an acceleration of 13m/s^2 nad having and electric field of 5N/C. So the formula in getting the charge is mutliply the mass and the quotients of Acceleration and the Electric Field so the answer is 1,146.6