Question

A flat coil, $C$ of $n$ turn, area $A$ and resistance $R$, is placed in a uniform magnetic field of magnitude $B$. The plane of the coil is initially perpendicular to $B$. The coil is rotated by an angle $\theta$ about a diameter and charge of amount $Q$ flows through it. The plane of the coil is initially kept parallel to $B$. The coil is rotated by an angle $\theta$ about the diameter perpendicular to $B$ and charge of amount $Q$ flows through it.Choose the correct alternatives

• A. $\theta ={90}^o,Q=\left(Ban/R\right)$
• B. $\theta ={180}^o,Q=\left(2Ban/R\right)$
• C. $\theta ={180}^o,Q=0$
• D. $\theta ={360}^o,Q=0$
• E. answer required

Answer 1

Answer: (A), (C), (D)

The correct options are
A $\theta ={90}^o,Q=\left(Ban/R\right)$
C $\theta ={180}^o,Q=0$
D $\theta ={360}^o,Q=0$

$n=$ number of turns

$A=$ Area

$R=$ Resistance

$B=$ Applied magnetic field

Further changing electric field produces magnetic field & changing magnetic field produces electric field for given condition, that the rotation of the coil is perpendicular thus when such rotations is along angles which are integral multiple of $\pi$ , charge $Q$ is zero.

i.e $Q=n\pi$

$n=1,2,.....$

$Q=0$