Two straignt conducting plates form an angle $\theta$ where their ends are joined. A conducting bar in contact with the plates and forming an isosceles triangle with them starts at the vertex at time $t=0$ and moves with constant velocity $\vec{v}$ to the right as shown in figure. A magnetic field $\vec{B}$ points out of the page. The magnitude of emf induced at $t=1$ second will be

• A

  $\mathrm{Bv} \tan \frac{\theta}{2}$
• Correct answer
  B

  $\mathrm{Bv}^2 \tan \frac{\theta}{2}$
• C

  $2 \mathrm{Bv}^2 \tan \frac{\theta}{2}$
• D

  $2 \mathrm{Bv}^2 \sin \frac{\theta}{2}$

Hence, the correct answer is option: 'B'.