SOLUTION

• In the case of DC motors Speed ∝ Back emf(Eb)/flux(φ)
• The field winding in the shunt motor is connected in parallel to the armature winding and the supply.
• The field winding is connected across the armature. The resistance offered by the field is constant so the current is constant.
• As current is constant flux also constant because the flux is directly proportional to current.since flux is constant so the speed is also constant because speed depends on flux.
• Hence the speed of the shunt motor can be assumed ALMOST constant under normal running conditions.