Answer / 1802.pranav

actually in stater of a vehicle there is one solenoid switch
which has one auxiliary and one main winding.so as soon as u
rotate the key of car,auxiliary winding comes into the
picture and 1st contact is made.in this situation motor runs
at low speed around 600rpm.But when 2nd switch comes into
contact due to main wdg then motor runs at max speed.and
when 2nd switch comes into contact it produces spark and
pushing action DUE TO WHICH HUMMING SOUND COMES.

Answer / s r mishra

humming noise is due to the pulsating torque in 1 phase induction motor.a 3 phase induction motor which has rotating torque does not make a humming noise.

Why electrical engineer use Cu Strip for transformer neutral why not GI Strip? What if we use GI instead of Cu does it affects the transformer performance.

7 Answers  

---

how to prepare PPM schudule

3 Answers   TATA,

---

cost of operation of which plant is least?

6 Answers  

---

What will happened. if we feed 3phase supplay to the stater with out insert the rotor. How much current will flow through the stater winnding?

2 Answers  

---

how electronic energy meter works?

2 Answers  

---

In 3pin or 5pin socket why the earth pin is bigger

3 Answers  

---

What is the Working principle of ELCB and RCCB?

1 Answers   Geo Miler, L&T,

---

What is E.M.F ?

6 Answers  

---

why three phase capacitor takes unbalanced current in capacitor bank?

0 Answers   Aggreko,

---

In electrostatic precipitator why positive terminal of tranformer rectifier unit is grounded?

2 Answers  

---

State the difference between Surge Arrester and Lightning arrester,Both are same or not?

7 Answers  

---

in 6.6 kv vaccum circuit breaker vaccum bottole vaccum capacity ????

0 Answers   Divis Laboratories,

---