resistance and circuits althea

What is resistance in electrical terms?

Resistance is the property of a material that slows down the flow of electricity and converts electrical energy into other forms.

What is the unit of measure for resistance?

Resistance is measured in ohms (\Omega).

Define a resistor.

A resistor is an electrical component that has a specific resistance.

What factors affect resistance?

1. Length of the material (longer = more resistance)
2. Cross-sectional area (inversely proportional to resistance; thinner = more resistance)
3. Type of material the current passes through.

How is voltage related to current according to Ohm's Law?

Voltage is directly proportional to current; if you increase voltage, current increases.

How are resistance and current related?

Resistance and current are inversely proportional; if resistance increases, current decreases.

What is a short circuit?

A short circuit is a circuit with a resistance too low, making current dangerously high.

What is electrical resistance?

Electrical resistance is the ratio of voltage to current.

What does Ohm's Law state?

Ohm's Law states that voltage equals current multiplied by resistance (V = I * R).

What are the conversions for common prefixes?

milli (m) -> (1/1000), kilo (k) -> (1000), mega (M) -> (1,000,000).

What are the two ways circuits can be connected?

1. Series: only one path for current to travel.
2. Parallel: more than one path for current to travel.

Describe the characteristics of series circuits.

In a series circuit:

• Electrons must travel through all components.
• If one part is not connected, current stops.
• Each load loses a portion of total voltage.
• Total voltage = sum of voltages lost on loads.
• Current is equal across components.

What happens to resistance and current in series circuits?

In series circuits, placing resistors in series increases the total resistance, leading to a decrease in total current.