Electric Charges and Fields — Physics STD 12 Science — Question

The thermal energy developed in a current-carrying resistor is given by U = i² Rt and also by U = Vit. Should we say that U is proportional to i² or i?

Which of the following methods can be used to measure the speed of light in water?

1. Roemer method.
2. Fizeau method.
3. Focault method.
4. Michelson method.

Define the S.1. unit of electric charge (coulomb).

Why does a diamond shine more than a glass piece cut to the same shape?

Two wires of equal length are bent in the form of two loops. One of the loops is square shaped whereas the other loop is circular. These are suspended in a uniform magnetic field and the same current is passed through them. Which loop will experience greater torque? Give reasons.

What is the force acting on a charge Q placed in an electric field E?

If the sum of all the forces acting on a body is zero, is it necessarily in equilibrium? If the sum of all the forces on a particle is zero, is it necessarily in equilibrium?

What is the specialty of sunglasses made from polaroid instead of ordinary glass?

Two nuclei have mass numbers in the ratio 1 : 8. What is the ratio of their nuclear radii?