Question

Squirrel cage induction motor is cheaper than slip ring motor.

Hint:

To remember this comparison: $$\text{Squirrel Cage} = \text{Cheaper, rugged, low starting torque, zero brush maintenance.}$$ $$\text{Slip Ring} = \text{Expensive, complex, high starting torque, requires regular brush tuning.}$$

Answer 1

Step 1: Analyzing Structural Elements:
A squirrel cage induction motor features a rotor constructed of solid copper or aluminum bars welded to short-circuiting end-rings. It has no insulated winding, no commutator, no slip rings, and no carbon brushes.

Step 2: Evaluating Materials and Labor Cost:
A slip-ring induction motor requires a fully insulated winding in its rotor, three polished copper slip rings on its shaft, carbon brushes, spring-loaded brush-holders, and external star-connected resistance starters. The material requirements and precision labor needed for slip-ring construction are dramatically higher.

Step 3: Conclusion:
Because of its simplified, highly robust, brush-less design, a squirrel cage motor is significantly cheaper to manufacture and maintain than a slip-ring motor of the same capacity. The statement is therefore True.