[问答题]
List the three ways thata/d fh3i dn2m. e4kf9cz bp8w1zmcl6 /d51beg an $emf$ can be induced in a loop of wire.
参考答案: 1. by changing the magnetic field
2. by changing the area of the loop in the field
3. by changing the loop's orientation with respect to the field
