Everything Science Grade 10

CHAPTER 17. ELECTRIC CIRCUITS 17.4

bbbbb b

V V V

V

V = 5V V = 5V V = 5V

V = 15V

zooming in

Consider the diagram below. On the left there is a circuit with a single resistor and a
battery.No matter where we measure the current, it is the same in a series circuit. On
the right, we have added a second resistor in series to the circuit. Thetotalresistance of
the circuit hasincreasedand you can see from the reading on the ammeter that the current
in the circuit has decreased.

V = 2 V

R = 2Ω

I = 0.67 A

Adding a resistor to the circuit

increases the total resistance

A

A

R = 1Ω

I = 0.67 A

V = 2 V

R = 2Ω

I = 1 A

The current in a series circuit

is the same everywhere

A

A

I = 1 A

(the current issmaller)

smaller)(the current is

General experiment: Voltage dividers

Aim:Test what happens to the current and the voltage in series circuits when addi-

tional resistors are added.

Apparatus:

• A battery


• A voltmeter


• An ammeter


• Wires


• Resistors

Physics: Electricity and Magnetism 291