Question

Voltage of bulb 5 volt and current is 500 mamp. Find resistance , power and energy in 2.5 hour?​

Answer 1

Answer:

For example:

A torch bulb is rated 5 V and 500 mA. Calculate (i) its power (i) resistance and (ii) energy consumed when it is lighted for 4 hours.

Answer:

Potential difference =V=5V

Current =I= 500mA=500x/1000 A=0.5 A

I) Power = V X I

= 5x0.5 =5x5/10=2.5 W

II)Reistance =R=?

By Ohm's law: V=IR

R=V/I

R=5/0.5  

=50/5 =10 ohms

III)Energy consumed when it is lighted for 4 hours

Energy =Power x time

t=4hrs=4x60x60

=2.5x 4x60x60

=36000joules/sec

Now you may try to get the answer to your questionby referring to the example given below!!

Answer 2

Given ,

Potential difference (v) = 5 volt

Current (I) = 500 ma or 0.5 a

Time (t) = 2.5 h or 9000 sec

We know that ,

V = IR

Thus ,

5 = 0.5 × R

R = 5/0.5

R = 10 ohm

$\sf \therefore \underline{The \: resistance \: is \: 10 \: ohm}$

Electric power (P) = VI

Thus ,

P = 5 × 0.5

P = 2.5 watt

$\sf \therefore \underline{The \: electric \: power \: is \: 2.5 \: watt}$

Electric energy = Power × Time

Thus ,

Electric energy = 2.5 × 9000

Electric energy = 22500 joule

$\sf \therefore \underline{The \: required \: electric \: energy \: is \: 22500 \: J }$