Two coaxial circular coils and have their centres coinciding

PHYSICS · Multi-part · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism

Problem

Two coaxial circular coils

C_1

and

C_2

have their centres coinciding. Coil

C_1

has

100

turns and radius

10\,\text{cm}

and carries a clockwise current of

2\,\text{A}

. Coil

C_2

has

50

turns and radius

5\,\text{cm}

. (i) Write, in symbols only, the expression for the magnetic field at the centre of a single circular coil of

n

turns, radius

R

and current

I

. (ii) Using the relation from part (i), obtain an expression for the net magnetic field at the common centre due to both coils when currents

I_{C_1}

and

I_{C_2}

flow through them. (iii) If the net magnetic field at the common centre is to be zero, calculate the magnitude and state the direction (clockwise or anticlockwise) of the current that must be passed through coil

C_2

. Show all steps clearly.

Related theory

Right-Hand Thumb Rule
Fields due to Currents
Biot-Savart law
Magnetic field on axis of circular loop
Moving Charges and Magnetism

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