Moving Charges and Magnetism - Result Question 29
30. A cylindrical conductor of radius $R$ is carrying a constant current. The plot of the magnitude of the magnetic field, B with the distance, $d$, from the centre of the conductor, is correctly represented by the figure :
[2019]
(a)
(b)
(c)
(d)
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Answer:
Correct Answer: 30. (c)
Solution:
- (c) Inside $(d<R)$
Magnetic field inside conductor
$B=K d$
This is straight line passing through origin
At surface $(d=R)$ $B=\frac{\mu_0}{2 \pi} \frac{1}{d}$
Maximum at surface
Outside $(d>R)$
$B=\frac{\mu_0}{2 \pi} \frac{1}{d}$
or $\quad B \propto \frac{1}{d} \quad \therefore$ Hyperbolic
