Moving Charges and Magnetism - Result Question 41

«««< HEAD:content/english/neet-pyq-chapterwise/physics/moving-charges-and-magnetism/moving-charges-and-magnetism-result-question-41.md

42. Two circular coils 1 and 2 are made from the same wire but the radius of the $1^{\text{st }}$ coil is twice that of the $2^{\text{nd }}$ coil. What potential difference in volts should be applied across them so that the magnetic field at their centres is the same

======= ####42. Two circular coils 1 and 2 are made from the same wire but the radius of the $1^{\text{st }}$ coil is twice that of the $2^{\text{nd }}$ coil. What potential difference in volts should be applied across them so that the magnetic field at their centres is the same

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/moving-charges-and-magnetism/moving-charges-and-magnetism—result-question-41.md (a) 4

(b) 6

(c) 2

(d) 3

[2006]

Show Answer

Answer:

Correct Answer: 42. (None)

Solution:

  1. (None) If $R_1 & R_2$ be the radius of the circular wires, $\frac{R_1}{R_2}=\frac{2}{1}$. If same potential is applied on them, current in Ist will be half that in the later. If $V$ potential is applied on them, current in them $=\frac{V}{2 R} & \frac{V}{R}$.

Now magnetic field at the centre of circular

coil, $=\frac{\mu_0 I}{2 r}$

For first wire, field $B_1=\frac{\mu_0 V}{2 R \times 2 R}$

For second wire, field $B_2=\frac{\mu_0 V}{2(R / 2) \times R}$

Given $B_1=B_2$

The given data do not provide any required result. There is a mistake in the framing of the question.