Question

In an AC generator, maximum number of lines of force pass though the coil when the angle between the plane of coil and lines of force is :

• A. $0^{\circ }$
• B. ${60}^{\circ }$
• C. ${30}^{\circ }$
• D. ${90}^{\circ }$

Answer 1

Answer: (D)

${90}^{\circ }$

Answer is D.

The emf is actually induced by a change in the quantity called the magnetic flux rather than simply by a change in the magnetic field. Magnetic flux is proportional to both the strength of the magnetic field passing through the plane of a loop of wire and the area of the loop. The value of the magnetic flux is proportional to the total number of lines passing through the loop. When the area is perpendicular, that is, at right angles (90 degrees) to the lines, the maximum number of lines passes through the area and the flux is a maximum. When the area is parallel to the lines, no lines pass through the area and the flux is 0.
Hence, maximum number of lines of force passes though the coil when the angle between the plane of coil and lines of force is 90 degrees.