Physics Final

Question 1

Potential difference

Answer 1

The potential difference between two points, A and B, is the energy given up by unit charge as it moves from point A to point B.

Question 2

Electric current

Answer 2

is the rate of flow of electric charge past a point.

Question 3

Potential difference

Answer 3

When charges lose energy by transferring electrical energy to other forms of energy in a component.
V is defined as the energy transferred per unit charge.

Question 4

e.m.f.

Answer 4

Is formally defined as the total work done when unit charge goes round a complete circuit.

Question 5

Ohm’s law

Answer 5

For a metallic conductor at constant temperature, the current in the conductor is directly proportional to the potential difference across its ends.

Question 6

Newton’s law of gravitation

Answer 6

Any two point masses attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of their separation.

Question 7

Gravitational field strength

Answer 7

The gravitational field strength at a point is the gravitational force exerted per unit mass on a small object placed at that point.

Question 8

Gravitational potential

Answer 8

Gravitational potential at a point is the work done in bringing unit mass from infinity to the point.

Question 9

Coulomb’s law

Answer 9

Any two point charges exert an electrical force on each other that is proportional to the product of their charges and inversely proportional to the square of the distance between them.

Question 10

Electric potential

Answer 10

The electric potential at a point is equal to the work done in bringing unit positive charge from infinity to that point.

Question 11

Electric field strength

Answer 11

The force per unit charge exerted on a stationary positive charge at that point.