A coil is placed in a magnetic field and has a flux Φ_B through it.The coil is stressed so that its area reduces to 60% of its original value.If the plane of the coil stays the same and the flux through it remains the same,how must the magnetic field change? A) It must increase by 60%. B) It must increase by 120%. C) It must decrease by 40%. D) It must increase by 67%.

Question

Quizplus · Accepted Answer

The magnetic flux Φ is given by Φ = B * A, where B is the magnetic field and A is the area. If the area decreases to 60% of its original value, the magnetic field must increase to maintain the same flux. The increase required is 1/0.6 - 1 = 0.67 or 67%.

A Coil Is Placed in a Magnetic Field and Has