Answer / ashli

when a motor rotates a back emf(E) is induced in the
armature which will oppose the supply voltage(V).. E is
proportional to the speed ie at zero speed there ll be no
back emf.. the current thro' the armature is (V-E)/R; where
R is the armature winding resistance(small value). at the
instant of starting speed is zero and so the value of E.
thus the current = V/R becomes very high.. once it attain
speed E is generated and current falls down

Answer / prakash suhane

During start motor requires high torque to get rated speed.
Requirement of high starting torque leads to large back
E.M.F and t6o overcome this back EMF high current flows
during starting of motor. once motor reached its rated
speed current reduced as per load current on motor.

Answer / rambabu

During start motor requires high torque to get stating load
is zero.also this will given lower o/p voltege per RPM.but a
higher current per phase

Answer / chreamz

During starting time, the motor acts like a blocked rotor.
The flux created on the armature turn to oppose that of the
rotor. Hence the motor amperage rises far beyond the
rating. It's estimated that, during starting time of the
motor, Operating Current = 6 times Norminal Current.

Answer / gaju

what is ripple component in ac supply?

I'm looking for a mnaual set for a Teradyne J750. Softcopy would be preferred but I'll take what I can get.

0 Answers  

why America use 60HZ 110V?

4 Answers   Kalindee Rail,

what is phase and neutral.

2 Answers   Birla,

what is back emf?

4 Answers   Bhel,

what is a tri vector meter? what are the tri vectors?

2 Answers  

what are the different sizes of U.G. cable & where these cabl;es are used according to voltage ..

0 Answers   HPCL,

What is the difference between EARTH & NEUTRAL?

13 Answers   L&T,

What is class 2 coordination ?

2 Answers  

Briefly describe three methods that are usually used by electricity suppliers to control voltage levels?

0 Answers  

which type of breaker sould be used for different level of voltage ? (i.e at 11 Kv, 33 Kv, 66 Kv....

8 Answers  

how can we represne the analog signal and digital signal if want to measure the speed and we have to use PLC

2 Answers  

what is meant by auto transformer?

4 Answers   Suzlon,