Electrical Circuits and Ohm’s Law

Monroe

There are two main kinds of circuits.1. Series circuits

a. Each part of the circuit is wired to the nextb. The amount of current (amps) is the same in all parts of the circuitc. If any part of the circuit is broken, no electricity can flow anywhere.

There are two main kinds of circuits.1. Series circuits (picture from sdsu-physics)

a. Each part of the circuit is wired to the nextb. The amount of current (amps) is the same in all parts of the circuitc. If any part of the circuit is broken, no electricity can flow anywhere.

2. Parallel circuits (picture taken from sdsu-physics)

a. Contains two or more different paths for electricity to travel throughb. Individual parts can be disconnected, without affecting other partsc. The amount of current can be different in different parts of circuit

Household electrical circuitsa. Use 115 volt, parallel circuits, wired in logical networks.b. Electricity moves from about 500,000 volts at power plant, to 10,000 volts at distribution points, to about 500 volts in neighborhoods, to 115 volts at the home.c. Enter the home at the fuse box, or circuit breaker.

Household electrical circuitsa. Use 115 volt, parallel circuits, wired in logical networks.b. Electricity moves from about 500,000 volts at power plant, to 10,000 volts at distribution points, to about 500 volts in neighborhoods, to 115 volts at the home.c. Enter the home at the fuse box, or circuit breaker.

Ohm’s law puts all of this together.Current (amps) = Voltage (Volts) ÷ Resistance (Ohms)

So if you have a 115 volt circuit, with an appliance that has 10 Ohms of resistance, it will pull 11.5 amps of current.

Ohm’s law puts all of this together.Current (amps) = Voltage (Volts) ÷ Resistance (Ohms)

So if you have a 115 volt circuit, with an appliance that has 10 Ohms of resistance, it will pull 11.5 amps of current.

So, if you cross the wires in a circuit, the resistance goes almost to zero, the current goes very high, the wires get hot, and the house burns down. THAT is why there are circuit breakers (usually more than one) in household electrical systems.