Important Laws

Question 1

Kirchoff’s First Law (and the related conservation)

Answer 1

The sum of the currents entering a junction is always equal to the sum of the currents leaving a junction (conservation of charge)

Question 2

Kirchoff’s Second Law (and the related conservation)

Answer 2

The sum of the E.M.F is equal to the sum of the p.d in a closed loop (conservation of energy)

Question 3

Ohm’s Law

Answer 3

The potential difference across a conductor is directly proportional to the current in the component as long as its temperature remains constant

Question 4

Newton’s First Law

Answer 4

A body will remain at rest or continue to move in a straight line at a constant velocity unless an external force acts on it

Question 5

Newton’s Second Law

Answer 5

The rate of change of momentum is directly proportional to the resultant force and takes place in the direction of the force.

f= changeP/changeT

Question 6

Newton’s Third Law

Answer 6

If object A exerts a force on object B, then object B will exert an equal and opposite force on object A