A semicircular wire of radius R is rotated with constant angular velocity ω about an axis passing through one end and perpendicular to the plane of the wire. There is a uniform magnetic field of strength B. The induced e.m.f. between the ends is:

Question

A semicircular wire of radius R is rotated with constant angular velocity ω about an axis passing through one end and perpendicular to the plane of the wire. There is a uniform magnetic field of strength B. The induced e.m.f. between the ends is: <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/p-ttn2ilfp4v1jk675.jpg" /> (A) Bω R2/2 (B) 2Bω R2 (C) is variable (D) none of these

Tardigrade Admin · Accepted Answer

e=(B ω L2/2) effective length of the wire frame is 2R ⇒ e=2Bω R2

Q. A semicircular wire of radius $R$ is rotated with constant angular velocity $ω$ about an axis passing through one end and perpendicular to the plane of the wire. There is a uniform magnetic field of strength $B .$ The induced e.m.f. between the ends is :

$B ω R^{2} /2$

$2 B ω R^{2}$

is variable

none of these

$e = \frac{B ω L ^{2}}{2}$
effective length of the wire frame is $2 R$
$\Rightarrow e = 2 B ω R^{2}$

Q. A semicircular wire of radius R is rotated with constant angular velocity ω about an axis passing through one end and perpendicular to the plane of the wire. There is a uniform magnetic field of strength B. The induced e.m.f. between the ends is :

BωR2/2

2BωR2