⚡ Part 1: Series Circuits

1. In a series circuit with three resistors (R₁ = 10Ω, R₂ = 15Ω, R₃ = 25Ω) connected to a 12V battery, calculate:

a) Total resistance (Rₜₒₜₐₗ)

b) Total current (I)

c) Voltage across each resistor

2. A series circuit contains a 6V battery and two resistors. If the current is 0.5A and one resistor has a value of 8Ω, what is the resistance of the second resistor?

🔌 Part 2: Parallel Circuits

3. Three resistors (R₁ = 12Ω, R₂ = 6Ω, R₃ = 4Ω) are connected in parallel across a 24V supply. Calculate:

a) Total resistance (Rₜₒₜₐₗ)

b) Total current from the supply

c) Current through each resistor

4. Which statement about parallel circuits is correct?

Voltage is different across each branch

Current is the same in each branch

Voltage is the same across each branch

Total resistance equals the sum of individual resistances

🔧 Part 3: Combination Circuits

5. In a combination circuit, R₁ = 8Ω and R₂ = 12Ω are in series with each other, and this combination is in parallel with R₃ = 10Ω. The whole circuit is connected to a 20V battery. Calculate:

a) Total resistance of the circuit

b) Total current from the battery

c) Current through the R₁-R₂ branch

d) Current through R₃

6. Draw the circuit diagram for question 5:

⚡ Part 4: Power Calculations

7. A 60W light bulb operates at 230V. Calculate:

a) The current through the bulb

b) The resistance of the bulb

c) The energy consumed in 4 hours (in kWh)

8. Which formula(s) can be used to calculate electrical power? (Select all that apply)

P = VI

P = I²R

P = V²/R

P = VR

🧮 Part 5: Complex Problem Solving

9. A household circuit has three appliances connected in parallel: a heater (2000W), a television (150W), and lights totalling 300W. All operate at 230V. Calculate:

a) The current drawn by each appliance

b) The total current from the mains supply

c) The cost of running all appliances for 5 hours if electricity costs $0.28 per kWh

10. In Kirchhoff's laws, complete the following statements:

Kirchhoff's Current Law: The sum of currents _______ a junction equals the sum of currents _______ the junction.

Kirchhoff's Voltage Law: The sum of all _______ drops around any closed loop in a circuit equals the applied _______.

🔍 Part 6: Circuit Analysis

11. Match the circuit type with its characteristic:

1. Series Circuit

2. Parallel Circuit

3. Combination Circuit

A. Contains both series and parallel elements

B. Same current through all components

C. Same voltage across all branches

12. Explain why household appliances are connected in parallel rather than in series:

13. A circuit breaker is rated at 20A. What is the maximum power that can be safely drawn from a 230V supply through this breaker?

📝 Part 7: Practical Applications

14. List three safety considerations when working with electrical circuits:

15. A car's headlight circuit has two 55W bulbs connected in parallel to a 12V battery. If the battery has a capacity of 60Ah, how long could the headlights operate before the battery is completely drained? (Assume 100% efficiency)

16. Why do Christmas lights often fail when one bulb burns out in older series-connected sets, but not in modern parallel-connected sets?