Q. calculate the value of the resistor to be connected in series with a 100W;
230V lamp so that the wattage of the lamp is reduced to 35W

Answer Posted / kalulu

lamp 100W/230v
when resistor R is connected in series with the lamp.
lamp power=35W
lamp Voltage= 230V /* since 230v is the operating voltage of the lamp*/
series current = 35/230
=0.152 A
power dissipated at a resistor = 100 W -35 W
= 65 W
= Isqr X R
R= 65/(0.152sqr)
= 2.8 kilo-ohm

Is This Answer Correct ?    0 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

How earthing of switchgear system to be done.

1460


Transformer how to maintaince a check b check c check d check

1536


why r we using shell transformer for low voltage

1547


A 3-PHASE TRANSFORMER IS USED TO STEP-DOWN THE VOLTAGE OF A 3-PHASE, 11KV FEEDER LINE. PER-PHASE TURNS RATIO IS 12.FOR A PRIMARY LINE CURRENT OF 20A, CALCULATE THE SECOUNDRY LINE VOLTAGE, LINE CURRENT AND OUTPUT KVA FOR FOLLOWING.A)STAR- DELTA.B)DELTA-DELTA.

2455


The shot circuit in any winding of transformer result? Explain

799






sometime battery charged and then automatically charged when rectifier ON conition, is there any chances please clarify the same.

1381


where rlc series ckt used?

1784


State uses of different types of stsrters with different capacities of motors as below: a. up to 5HP b. above 5hp to 10hp c. above 10hp to 20hp d. above 20hp

1477


What are the advantages of autotransformer?

765


Why 1/3 is used in symmetrical components?

1390


Is there any Electrical supervisor license which gives permit to work whole India rather than individual state??

1395


What is the difference between electrical earthing and electrical grounding?

688


lenz law application and define

2226


take 100kva DTR( delta/wye ), what ll happen if we connect 11kv to LT side instead of connecting to HT side? will the DTR behave as a step up transformer or something else????

1817


What happen when change order of CT in GIS feeder?

1186