Explanation

Sure, let’s break it down. In a regenerative braking system, when the motor is acting as a generator, it generates an electromotive force (emf) due to the motion of the rotor. This emf is commonly referred to as the “back emf” because it opposes the applied voltage that’s trying to keep the motor running. Now, during regenerative braking, the motor’s rotor is still spinning, but the applied voltage is reduced or even reversed to slow down or stop the motor. Since the rotor is still in motion, it generates a back emf. For regenerative braking to be effective, this back emf needs to be greater than the applied voltage. This ensures that energy is being returned to the power source rather than being dissipated as heat in traditional braking systems. So, option C states that the back emf of the rotor is more than the applied voltage, which aligns with the principle of regenerative braking.