Answer Posted / n.muthukumar

ups backup time=battery AH*battery efficiency*no.of
batteries/ups capacity in kva*130*output power factor

for example:65*0.9*10/5*130*0.8=1.125

approximately:1hr 15min

Circuit diagram of tube light without starter using electrical choke

4137

---

What will be the output voltage of a transformer if it is primarily energized from a square wave voltage source?

1109

---

What are the different types of dams?

1245

---

The loads are connected with phase and ground then why current flow as the loads ?

1979

---

Please tell me the power flow from pmg to main rotor of an alternator (Including AVR unit)?

2039

---

Briefly describe means used by electricity suppliers to influence the flow of active and reactive power in power networks (one for each type)?

1977

---

Wind mill

1899

---

with help of neat sketch explain principle of TIG welding process

1979

---

How do we arrive at selecting reactive capacitance value as 30% of h.p rating of motor?

1846

---

what is differant beetween overload current and phase current?

2346

---

Which do you think is the most significant cause of energy loss in a factory?

2248

---

While testing LA mast,What are the parameter limits ?

1911

---

how  do you choose the cable size as per amps rating & the voltage drop for the same.

1789

---

How Can You Relate Power Engineering With Electrical Engineering?

1245

---

how to calculate short circuit current for the busbar

1515

---