Physics
posted by susane .
Thanks for any help :)
Four 20 ohm resistors are connected in parallel and the combination is connected to a 20V emf device. The current is:
A) 0.25A
B) 1.0 A
C) 4.0 A
D) 5.0 A
E) 100 E
Parallel circuits:
I know that the voltage is 20V and the Resistance is 20 V. So, I divided I=V/R
I= (20/20)=1 The current for a parallel circuit is found by I= I + I+ I+I
The current is 1 so therefore I total would be 4 or C.
Four 20 ohm resistors are connected in series and the combination is connected to a 20V emf device. The potential difference across any one of the resistors is:
A) 1 V
B) 4 V
C) 5 V
D) 20V
E) 80 V
So there are four resistors that are 20 ohms. Their connected to a 20 V device. The question wants to known volts. Its says for a parallel circuit. I just dividied 20V/4 and got 5V.Is that ok to think of it that way?
Thank you
correct on the first. However, if the second circuit is parallel, each resistor has 20V across it.

A potential difference of 2.0 V is applied across a wire of cross sectional area 2.5 mm^2. The current which passes through the wire is 3.2 × 103 A. What is the resistance of the wire?