Physics, asked by adibro41, 1 year ago

An electric bulb is rated 220V and 100W.When it is operated on 110V, then the power consumed will be?I have already solved it but my answer is not coming.please tell me where I have made mistake.Sorry for bad handwriting

Attachments:

adibro41: Firstly, I used p=vi

adibro41: from that I got current=5/11 ampere

Answers

Answered by aaaa483

P=V×V/R

As in both cases Resistance is same..

so,

P is proportional to V square

P1/P2=V1square/V2square

100/P2=220×220/110×110

P2=25watt

Hope it helps you....

and hope its easy for you to crct your mistake....

aaaa483: you know this

adibro41: simply we can say current changes with changing voltage

adibro41: and resistance doesn't change

adibro41: ok?now Ryt?

aaaa483: yes

adibro41: how do you know that current changes with p.d.

aaaa483: here resistance will not cange we are not changing material or radius or length something

aaaa483: Because Voltage is capacity how much current will from the object will flow

adibro41: ya I got it

aaaa483: ok

Answered by Ansh123721

Answer:

R = 220^2/100 Ω = 484 Ω. ...

When V = 110 V,

power consumed = V^2/R = 110^2 /484 = 25 W.

here we have taken the value of I=v/r in p=vi

p= V^2/r. (putting value of I=v/r in this)

hope this answer useful to you and pls make brainlist pls

adibro41: I know formula that p=v^2/r

adibro41: But p=vi can also be used

Ansh123721: ok give me some time to think

Ansh123721: pls

adibro41: you understood my point?

adibro41: see my solution

Ansh123721: in CLS 10 I have also doubt on this question

adibro41: Ya why can't we use p=vi

Ansh123721: yes I understood what you are telling to me

adibro41: ok...

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