Lenz Law and the Direction of emf What direction is the magn

Lenz\' Law and the Direction of emf What direction is the magnetic force as the loop enters, moves through, and leaves the field region? (Remember, F-lLxB) A) up, none, down B) Down, down, down C) Up, down, up Up, none, up E) Down, none, up Physics 240 Unit 17, Slide 27

Solution

According to Lenz\'s law ,The direction of induced emf is opposite to the direction of change in magnetic flux.

When the loop enter into a megnetic field , the direction of change in magnetic flux is in downward direction.So, the direction of induced emf is opposite to the down ward direction i.e., along up ward direction.

When the loop moves in a megnetic field , the change in magnetic flux is zero.So, the induced emf in the loop is also zero.

So, the direction of induced emf is none.

When the loop leaves a megnetic field , the direction of change in magnetic flux is in downward direction.So, the direction of induced emf is opposite to the down ward direction i.e., along up ward direction.