Question

A straight conductor of mass m and carrying a current i is hinged at one end and placed in a plane perpendicular to the magnetic field B as shown in figure. At any moment if the conductor is let free, then the angular acceleration of the conductor will be (neglect gravity) –

• A.
• B. $\frac { 2 } { 3 } \frac { \mathrm { iB } } { \mathrm { m } }$
• C. $\frac { 3 \mathrm { iB } } { 2 \mathrm {~m} }$
• D. $\frac { 3 \mathrm { i } } { 2 \mathrm { mB } }$

Answer 1

Answer: (C)

$\frac { 3 \mathrm { iB } } { 2 \mathrm {~m} }$

Answer 2

Torque dt = dF × r = iBdr × r t = a =

= =