What is radial field? What is its purpose?

Describe the principle and working of a d.c. motor. Label each part of this motor and state three factors that increase the speed the motor.

The figure shows a part of the circuit diagram. Name the instrument $X$ connected in this circuit. Give reason for your answer.

The figure shows a part of circuit diagram. Name the instrument $Y$ connected in this circuit. Give a reason for your answer

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