P2 - Resistors in Series and Parallel

What is the equation to calculate resistance using potential difference and current?

Resistance (Ω) = Potential Difference (V) ÷ Current (A)

How do you calculate current if you know potential difference and resistance?

Current (A) = Potential Difference (V) ÷ Resistance (Ω)

What is the total resistance of resistors connected in series?

The sum of their individual resistances

How do you calculate total resistance for resistors in series?

Total Resistance = R₁ + R₂ + R₃ + ...

Why do resistors in series add together?

Because current must pass through each resistor one after the other and cannot bypass any resistor

What is equivalent resistance?

A single resistor that can replace a combination of resistors without changing the current or potential difference in the circuit

If you have a 100 Ω and a 50 Ω resistor in series, what is the total resistance?

150 Ω

How do you calculate current in a circuit with resistors in series?

Current = Total Potential Difference ÷ Total Resistance

If a circuit has a 20 V supply and a total resistance of 150 Ω, what is the current?

0.13 A (to two decimal places)

What is the total resistance of a 20 Ω, 15 Ω, and 10 Ω resistor in series?

45 Ω

How do you calculate the potential difference across resistors in series?

Potential Difference = Current × Total Resistance

If a current of 0.5 A flows through resistors with a total resistance of 275 Ω, what is the potential difference?

137.5 V

What is the rule about total resistance for resistors in parallel?

The total resistance is less than the resistance of the smallest individual resistor

Why is the total resistance lower in parallel circuits?

Because there are multiple pathways for the current, increasing total current flow

If you have two resistors in parallel, one 150 Ω and one 200 Ω, is the total resistance greater than, less than, or equal to 150 Ω?

Less than 150 Ω

Why does total resistance decrease when resistors are connected in parallel?

Because the current has more pathways, so more current flows for the same potential difference

What is the unit for resistance?

Ohm (Ω)