WOLFRAM|DEMONSTRATIONS PROJECT

Resistors in Series

voltage V in volts

3.75

resistance

R

1

in ohms

0.1

resistance

R

2

in ohms

0.1

close circuit

The current in a circuit can be calculated by using Ohm's law: voltage equals resistance times current. In symbols,

V=IR

. In this simple circuit, the two resistors are in series, so the effective resistance

R

tot

=

R

1

+

R

2

. The current is then

I=

V

R

1

+

R

2

. No current flows when the circuit is open.