Example 6.2 A square loop of side 10 cm and resistance 0.5 l is
placed vertically in the east-west plane. A uniform magnetic field of
0.10 T is set up across the plane in the north-east direction. The
magnetic field is decreased to zero in 0.70 s at a steady rate. Determine
the magnitudes of induced emf and current during this time-interval.
Answers
Answer:
The induced emf is 1.01 × 10-3 V and the current is 2.02 × 10^(-3) A
Explanation:
According to the problem the side of the loop is 10 cm or 0.1 m
and the resistance of the square loop is 0.5 I
The magnetic field , B = 0.10 T
Therefore Area of the loop is , A = (0.1)^2m = 0.01 m
As the current is flowing in east- west direction and the magnetic field is set at north to east direction
Therefore the angle between them, θ = 45°
Therefore,
The magnetic flux,
ϕ = A x B x cosθ
= (0.01)(0.1)(cos45)
= 7.07 × 10-4 Wb
According to the problem the magnetic field is decreased to zero in 0.70 s
Therefore, the induced emf = e = -dϕ/dt = -(7.07 × 10-4)/0.70
e = -1.01 × 10-3 V
Therefore the current within the loop = 1.01 × 10-3/0.5 = 2.02 × 10^(-3) A