Question

a coil of 40 ohm resistance, 100 turns and radius 6mm is connected to ammeter of resistance 160 ohm. coilis placed perpendicular to the magnetic field. when coil is taken out of the field 32 microcoulomb charge flows through it. the magnetic flux density is:


6.55T

5.66T

2.55T

0.566T

0.0566T

Answer 1

avg current = total charge flow / time ...

Answer 2

Answer:

The magnetic flux density is 0.566 T.

Explanation:

Given that,

Radius r = 6 mm

Resistance of coil =40 ohm

Number of turns = 100

Resistance of ammeter = 160 ohm

Total resistance R= 200 ohm

Charge $q= 32\times10^{-6}\ C$

We know the induced emf is

$\zeta=\dfrac{\Delta\phi}{\Delta t}$

$IR=\dfrac{\Delta(BA)}{\Delta t}$

$\dfrac{\Delta Q}{\Delta t}R=\dfrac{\delta(B\cdot A)}{\Delta t}$

$\Delta B=\dfrac{\Delta Q\cdot R}{A}$

The area is

$A= N\pi r^2$

$A= 100\times3.14\times(6\times10^{-3})^2$

$A= 0.011304$

The magnetic flux density is

$\Delta B=\dfrac{32\times10^{-6}\times 200}{0.011304}$

$\Delta B=0.566\ T$

Hence, The magnetic flux density is 0.566 T.