When two D.C. series motors are connected in parallel, the resultant speed is
A. More than the normal speed
B. Loss than the normal speed
C. Normal speed
D. Zero
Answer: Option A
Solution(By Examveda Team)
When two DC series motor are connected in parallel then the resultant speed is more than the normal speed. If the voltage across each motor is V and current through each motor in parallel connection is $$\frac{I}{2}.$$ So$${\text{speed}} \propto \frac{{{\text{voltage}}}}{{{\text{current}}}} \propto \left( {\frac{{\text{V}}}{{\frac{{{I_{\text{a}}}}}{2}}}} \right) \Rightarrow 2\left( {\frac{{\text{V}}}{{{I_{_{\text{a}}}}}}} \right)$$
Hence the resultant speed is more than normal speed.
This Question Belongs to Electrical Engineering >> D.C. Motors
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Comments ( 3 )
The condition for maximum efficiency for a D.C. generator is
A. Eddy current losses = stray losses
B. Hysteresis losses = eddy current losses
C. Copper losses = 0
D. Variable losses = constant losses
If a D.C. motor is connected across the A.C. supply it will
A. Run at normal speed
B. Not run
C. Run at lower speed
D. Burn due to heat produced in the field winding by eddy currents
The speed of a D.C. shunt motor can be increased by
A. Increasing the resistance in armature circuit
B. Increasing the resistance in field circuit
C. Reducing the resistance in the field circuit
D. Reducing the resistance in the armature circuit
The armature voltage control of D.C. motor provides
A. Constant torque drive
B. Constant voltage drive
C. Constant current drive
D. None of the above
Any ckt connected in parallel than current is increased (voltage constant)
Current proportional fie esliye fie increased and speed decreased
When two motors connect in parallel the current taken by them remain the same as the single one....because the resultant resistance will also be half.....
Your answer is wrong. when two dc series motor is connected in series the current I is flowing through two dc series motor.These two dc series motor shares the supply voltage(V/2) Where V is the supply voltage.When these two dc series motor connected in parallel the current through each dc series motor is reduced I/2. flux is directly proportional to (I/2) and flux is inversely proportional to speed.So speed increases to 4 times of the normal speed.
The correct answer is A.more than normal speed