Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectromagnetic Induction
A right-angled triangle abc , formed from a metallic wire, travels at a uniform speed v in its plane. A uniform magnetic field B is present in the perpendicular direction. Determine the induced emf in the segment ab .
Options
- AvB(bc) , positive at a
- BvB(ab) , positive at a
- CvB(bc) , positive at b
- D0
Correct answer
C. vB(bc) , positive at b
Step-by-step solution
The motional emf induced in a straight conductor is given by = ( v B ) l . The velocity v is directed towards the right and the uniform magnetic field B is directed outwards (out of the plane of the paper). By the right-hand rule, the direction of the cross product v B is downwards (from b to c ). This indicates that the magnetic force pushes positive charges towards the end c , making the potential at c higher than at b . Thus, the end c acquires a positive polarity. The magnitude of the induced emf in the segment