Use Lenzâs law to answer the following questions concern- ing the direction of induced currents. Express your answers in terms of the letter labels a and b in each part of Figure P31.20. (a) What is the direction of the induced current in the resistor R in Figure P31.20a when the bar magnet is moved to the left? (b) What is the direction of the current induced in the resistor R immediately after the switch S in Figure P31.20b is closed? (c) What is the direction of the induced current in the resistor R when the current I in Fig- ure P31.20c decreases rapidly to zero?
