Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectromagnetic Induction
A square-shaped copper coil with edges of length 50 cm contains 50 turns. It is placed perpendicular to a 1.0 T magnetic field. The coil is removed from the magnetic field in 0.25 s and restored to its original place in the subsequent 0.25 s . The resistance of the coil is 25 . Assuming the coil moves with uniform velocity during its removal and restoration, determine the thermal energy developed in the coil during i
Options
- A12.5 J
- B100 J
- C25 J
- D50 J
Correct answer
C. 25 J
Step-by-step solution
Area of the coil, A = (0.5)^2 = 0.25 m ^2 Total change in magnetic flux during restoration, = NBA = 50 1.0 0.25 = 12.5 Wb Since the coil moves with uniform velocity, the induced emf is constant: = t = 12.5 0.25 = 50 V Thermal energy developed during restoration is given by: H = ^2 R t = (50)^2 25 0.25 = 100 0.25 = 25 J