Question

2 lamps 100W ,220V and 60W,220V are connected in parallel to mains.find the current drawn by 2bulbs and all total I

Answer 1

Case 1

Power = 100w

And volt = 220v

We know p = vi

So, 100 = 220 × i

100/220 = i

So i = 0•45

Now r =v/i

R=220/0•45

R =488•88

Case 2

P = 60w

And v = 220v

And we know

P = vi

P/ v = i

60/220 = i

So i = 0•27

R = v/i

R = 220/0•27

R = 814•81

Now they are connected in parallel

So,

1/Rp = 1/488.88 + 1/814.81

1/Rp = 1/ now take lcm and solve take total current from

I = V/R

Hope ! this will help you