What Is the Potential Difference Across Three Series Resistors?

[name_ask17]

Homework Statement

Three resistors, 21, 43, and 73 , are connected in series, and a 0.55 A current passes through them. What is
(a) the equivalent resistance and
(b) the potential difference across the three resistors?

Homework Equations

i tried to use EPE/q by putting the equivalent resistors/1.6E-6 charge. i don't think this is right though :/

The Attempt at a Solution

I got a as 137 and that is correct but i can't seem to get part b.

 

[gneill]

You want Ohm's Law. Look it up!

 

[name_ask17]

v=IR, but how does that help me find potential difference?

 

[gneill]

v=IR, but how does that help me find potential difference?

What do the variables in the formula represent?

 

[name_ask17]

volts=resistance(current)
is potential difference under volts?...because i tried 11*25 but that was marked incorrect by my online homework

 

[gneill]

Potential difference is given in volts.
Current is given in Amps.
Resistance is given in Ohms.

You have the resistance and the current. Find the voltage.

 

[name_ask17]

what is my current?
and do i use the the equivalent capacity as resistance?

 

[gomunkul51]

(b) each of the three resistors or across all of them together?
If it is the later: delta V = IR_total

** the current is the same through each of them and all of them (connection in series).

 

[name_ask17]

the question just says the potential difference across the three resistors; so i think it might be the total. but i am still confused on which part is the current

 

[gneill]

the question just says the potential difference across the three resistors; so i think it might be the total. but i am still confused on which part is the current

It is explicitly stated in the problem.

 

[gomunkul51]

"I" is the current.
In your case: 0.55 A i.e. 0.55 Ampere (a unit of electric current).

Your question suggests you need to go back to your notebook/coursebook and reading that chapter again (Ohm's Law in a series circuit) and mostly looking at the examples and the implementation of the law.

good luck.

 

[name_ask17]

YYYEESSS!. thank YOU.
also thanks for putting up w/me thru this problem
i was making it harder than it is