Question

(iv) Observe the diagram and answer the sub-questions :
(a) Which principle
explained in this figure?
is
(b) Which rule is used to find
out the direction of force
in this principle?
(c) In which machine this
principle is used.
​

Answer 1

a) Principle explained in the figure is about the electromagnetic force also called as Lorentz force.

• When a charged particle moves through an Electromagnetic field with a velocity v, it will experience a force.
• The direction of the force depends on the direction of motion of charge and the direction of magnetic field.

b)The direction of force is determined using Fleming's left hand rule

• Left hand is kept such that, when the pointing finger denotes the direction of magnetic field and middle finger in the direction of current, then thumb indicates the direction of force.

• In the figure field from north pole to south pole. When current is flowing downward in the copper wire,it moves outward. When current is towards up,wire moves into the circuit.

c)This principle is used in electric motors.

• Magnetic field is applied on a current carrying coil which enable it to rotate according to the thumb rule. Due to this motion the shaft attached moves and perform mechanical work.