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If the load current and flux of a DC motor are held constant, and voltage applied across its armature is increased by 10%, its speed will
- ADecrease by 10%
- BRemain unchanged
- CIncrease 10%
- DIncrease by 20%
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CCommunity
We know that, in a dc motor
$({E_b} = V - {I_a}{R_a})$
$(N \propto \frac{{{E_b}}}{\phi })$
As voltage applied across its armature is increased by 10%, back emf also gets increased by 10%.
As flux is constant and speed is directly proportional to back emf, speed also gets increased by 10%.
$({E_b} = V - {I_a}{R_a})$
$(N \propto \frac{{{E_b}}}{\phi })$
As voltage applied across its armature is increased by 10%, back emf also gets increased by 10%.
As flux is constant and speed is directly proportional to back emf, speed also gets increased by 10%.