An electric motor operating on a 60 V dc supply draws a current of 10 A. If the efficiency of the motor is 50%, the resistance of its winding is 

1. 3Ω

2. 6Ω

3. 15Ω

4. 30Ω

Which of the following devices is not based on Faraday's law of electromagnetic induction?

1. AC generator

2. Speedometer

3. Induction motor

4. DC motor

A simple electric motor has an armature resistance of $1\mathrm{\Omega }$ and runs from a d.c. source of 12 V. It draws a current of 2 A when unloaded. When a certain load is connected to it, its speed reduces by 10% of its initial value. The current drawn by the loaded motor is

1. 3 A

2. 6 A

3. 2 A

4. 1 A