Question

Fig. shows some of the equipotential surfaces of the magnetic scalar potential. The magnetic field at a point in the region is–

• A. 2 × 10^–5 T
• B. 10^–5 T
• C. 10^–4 T
• D. 2 × 10^–4 T

Answer 1

Answer: (D)

2 × 10^–4 T

Answer 2

B = – $\frac { \mathrm { dV } _ { \mathrm { B } } } { \mathrm { dx } }$ = $\frac { 2 \times 10 ^ { - 5 } - 1 \times 10 ^ { 5 } } { ( 0.1 ) \sin 30 ^ { \circ } }$ = 2 × 10^–4 T