Question

the resistance of a circular coil of 50 turns and 10 cm diameter is 5 ohm what must be the potential difference across the ends of the coil so as to nullify the Earth's magnetic field (H=0.314 gauss) at the centre of the coil how should the coil be placed to achieve this result​

Answer 1

Please find the answerin the attachment.

Hope this helps. ..

Answer 2

Answer:

The potential difference across the ends of the coil is 0.25 V.

Explanation:

Given that,

Number of turns = 50

Diameter = 10 cm

Resistance = 5 ohm

Magnetic field $H= 0.314 Gauss = 0.314 \times10^{-4}\ T$

We need to calculate the current

Using formula of magnetic field

$H= \dfrac{\mu_{0}NI}{2r}$

$I=\dfrac{2rH}{\mu_{0}N}$

Put the value into the formula

$I=\dfrac{2\times5\times10^{-2}\times0.314 \times10^{-4}}{4\pi\times10^{-7}\times50}$

$I=0.0499\ A$

We need to calculate the potential difference

$V= I\times R$

$V=0.0499\times5$

$V=0.25\ V$

Hence, The potential difference across the ends of the coil is 0.25 V.