Question

For this circuit, what will be the voltage drop across R3 ?

21.3 V

14.2 V

45.0 V

9.47 V

Answer 1

45.0 V?

Answer 2

@TheSmartOne

Answer 3

This is in the wrong subject. Probably why you're not getting any answers

Answer 4

Moved to physics.

How did you get to 45 V?

Answer 5

ops i didnt check where i had submitted it! i think i did it wrong okay so to find the voltage drop isnt it current *total resistance ?

Answer 6

first you have to find the current

So you first get total resistance and then you can find the current

And since these resistors are in series, the current is the same for all of them

Answer 7

i found that the total resistance was 95

Answer 8

And then you use ohm's law
V = IR

You have the current and you plug in the resistance of R3
And tada you have the voltage drop across R3

Answer 9

the current is 45/95 right ?

Answer 10

so 0.47 ?

Answer 11

Yes, that's good now use Ohm's law to calculate the current since we know the voltage

Answer 12

You're moving in the right direction!

Answer 13

then the voltage drop would be 21.3 ?

Answer 14

you just multiply them right ? 0.47 * r3 which is 45 ?

Answer 15

wait i think im getting confused

Answer 16

No you did it right! That's correct

You just multiply the current by each resistor's resistance

And that's how you'd calculate the voltage drop across each resistor

Answer 17

Remember this is only in series

In parallel, we wouldn't have a voltage drop since voltage would all be the same

Answer 18

oh really i did it right ? when i tried calculating it i got 21.2 , its off by 1 is that okay ?

Answer 19

It's because you simplified when you did 45/95

If you put the exact value you'll get 21.3

You just rounded too early

Answer 20

ohh okay lol makes sense! awesome thank you

Answer 21

You're welcome!