# Ohm’s Law.

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Ohm’s Law

Ohm’s Law

Measuring Current Current is measured in units of amperes (A)
In a series circuit, current is the same at all the points In a parallel circuit, current is shared between all the points

What is the current? SERIES CIRCUIT PARALLEL CIRCUIT 3A 3A 4A 1A 4A 1A

Measuring Voltage Voltage – the electrical push that a cell/battery gives to the current Voltage is also known as Potential Difference Voltage is measured in units of volts (V)

Measuring Voltage 3V 1.5V 3V In a series circuit, voltage is shared between all the points In a parallel circuit, voltage is the same at all the points

What is the current and voltage?
Series Same Shared Parallel

What is the current and voltage?

Measuring Resistance Resistance – slows down current, adding components to a circuit increases resistance Resistance is measured in units of ohms (Ω) More resistance = Less current = Less light In a series circuit, add up all resistance to get total.

Electrical Power

What is the current?

What is the current?

What is the current?

How much voltage gives 5 amps of current through a 3 Ω light bulb?
I = V/R V = (5A)  (3Ω) V = 15V

How much current flows in a circuit with a 1
How much current flows in a circuit with a 1.5 volt battery and three 1 ohm resistances (bulbs) in series? I = V/R I = (1.5V) / (3Ω) I = .5A

What is the voltage drop across each resistor in the circuit?
In a series circuit, voltage is shared between all the points 9V/3 = 3V

A light bulb with a resistance of 1. 5Ω is connected to a 1
A light bulb with a resistance of 1.5Ω is connected to a 1.5V battery in the circuit. Calculate the power used by the light bulb? P = IV I = V/R I = (1.5V)  (1.5Ω) I = 2.25A P = (2.25A)  (1.5V) P = W