Year 9 Electricity Test 2025 Review

Test Structure and Mark Distribution

The Year 9 Electricity Test for 2025 is divided into three primary sections with a total possible score of 50 marks. A separate bonus section is included for reflection on household electronic devices.

• Section A: Multiple Choice Questions — 15 marks

• Section B: True and False Questions — 5 marks

• Section C: Short Answer Questions — 30 marks

Section A: Multiple Choice Questions

1. Insulating Materials     Which of the following materials is an insulator?      a. Copper     b. Nickel     c. Rubber     d. Aluminium

2. Series Circuit Faults     If one light globe in a series circuit goes out, what happens to the other light globes?      a. They all become brighter.     b. They all remain lit.     c. They all go out.     d. They all become dimmer.

3. Definition of Charge Flow     The continuous flow of charge in a wire is called:  a. An electric current     b. An electric circuit     c. Electrical resistance     d. An electrical conductor

4. Direction of Electron Flow     When a charged battery is connected to a closed-circuit, electrons flow from:      a. Left to right     b. North to south     c. Negative to positive     d. Positive to negative

5. Factors Influencing Resistance     The resistance of a wire does NOT depend on the:     a. Type of material the wire is made from.     b. Length     c. Thickness of the wire     d. Voltage applied across the wire.

6. Relative Brightness in Bulbs     In a circuit constructed with three identical light bulbs, where bulb 1 is in a main branch and bulbs 2 and 3 are in parallel branches after the first bulb, the predicted brightness is:      a. Light bulb 1 is brighter than Light bulb 2, which is brighter than Light bulb 3.  b. Light bulb 1 is dimmer than Light bulb 2, which is dimmer than Light bulb 3.  c. Light bulb 1 is brighter than light bulbs 2 and 3, which both have the same brightness.      d. Light bulb 1 is dimmer than light bulbs 2 and 3, which both have the same brightness.

7. Ohm's Law Calculation     A circuit contains one light bulb, draws a current of $3A$, has two wires and connects to a $6V$ battery. The resistance of this circuit is calculated as:       a. $2.0\,\Omega$     b. $3.0\,\Omega$     c. $6.0\,\Omega$     d. $18.0\,\Omega$

8. Total Resistance in Series     In a series circuit, the total resistance is equal to:     a. $R_1 + R_2$     b. $R_1 \times R_2$     c. $R_1 - R_2$     d. $R_1 \div R_2$

9. Measuring Current     Correct identification of circuit diagrams is required to determine which incorrectly indicates how to measure current (noting that ammeters must be in series). a. Diagram A b. Diagram B c. Diagram C d. Diagram D

10. Relationship Between Resistance and Current     If you increase resistance in a series circuit, what happens to the current?       a. The current will also increase.     b. The current will decrease.     c. The current will be zero.     d. There is no change to the current.

11. Static Electricity Examples     Identify which scenarios relate to static electricity:     I. Rubbing a balloon with wool to make it stick to a wall.     II. Connecting a battery in a circuit to turn on a light bulb.     III. Plugging a cellphone into an electrical outlet to charge.     IV. Using hair conditioner to prevent the buildup of electric charges in hair.     Choices: (A) I and III, (B) I and IV, (C) II and III, (D) II and IV.

12. Voltmeter Readings in Series     In a series circuit where voltmeter $V_2 = 6V$ and $V_3 = 6V$, the total reading on $V_1$ (measuring across both) would be:     a. $27V$     b. $12V$     c. $3V$     d. $9V$

13. Electrostatic Interactions     Two small plastic balls attached to strings are shown repelling each other. What can be inferred about the charges on the balls?     a. The charges are the same because the balls are attracted to each other.     b. The charges are the same because the balls are repelling each other.     c. The charges are different because the balls are attracted to each other.     d. The charges are different because the balls are repelling each other.

14. Garage Circuit Logic     In a garage circuit with a furnace motor, light bulb, exhaust fan, and doorbell:     Which components will be turned on when Switch 1 is closed and Switch 2 remains open?     a. The furnace motor, the light bulb, and the exhaust fan only     b. The furnace motor, the light bulb, and the doorbell only     c. The light bulb and the exhaust fan only     d. The light bulb and the doorbell only

15. Current Measurement Reading     In a diagram showing a multimeter measuring current, the value is identified as:     a. $170\,mA$     b. $385\,mA$     c. $170\,mV$     d. $385\,mV$

Section B: True and False Questions

Determine the veracity of the following statements based on a provided circuit diagram featuring bulbs and a bell:

1. There are no switches in this circuit. (True/False)

2. The three lightbulbs are in parallel. (True/False)

3. The light bulbs would be lit, and the bell would be ringing. (True/False)

4. A meter for measuring the current is attached. (True/False)

5. If the bell stops working, the lights will go out. (True/False)

Section C: Short Answer Questions

Question 1: Circuit Fundamentals and Symbols (8 Marks)

• Circuit Components: List the three components that an electrical circuit needs.

• Standard Symbols: Draw the graphical symbol for the following:

  • Open Switch

  • Voltmeter

  • Battery

  • Light Globe

  • Ammeter

  • Resistor

• Series and Parallel Analysis: Using four diagrams (A, B, C, D) with identical globes and $6V$ batteries, identify:     i. In which circuit/s are the bulbs connected in series?     ii. In which circuit/s would the bulbs be the brightest?     iii. In which circuit/s would the bulbs be the dimmest?

Question 2: Metering and Circuit Types (5 Marks)

• Connection Methods: Compare how an ammeter and voltmeter would be connected in a circuit.

• Operational Differences: Identify two differences between an ammeter and a voltmeter beyond their connection methods.

• Current and Voltage Comparison: Complete the table using terms "same" or "different":

  • Series Circuits: Current behavior vs. Voltage behavior.

  • Parallel Circuits: Current behavior vs. Voltage behavior.

Question 3: Torch Mechanics and Energy (5 Marks)

• Circuit Diagram: Draw a simple circuit diagram representing a torch as a closed circuit.

• Functional Explanation: Explain how a torch works, utilizing the specific terms: electric current, batteries, electric circuit, and switch.

• Energy Transformation: Describe the energy transformation occurring within this specific circuit.

Question 4: Switch Logic and Circuit Analysis (5 Marks)

• Switch Scenario Table: Determine if Globe 1, Globe 2, and Globe 3 are "on" or "off" for the following active switches:

  • A, B, C, and D

  • A, B, and E

  • A, C, D, and E

  • A, B, D, and E

• Uniform Brightness: Identify which switch(es) must be closed so that three identical globes (G1, G2, and G3) all have the same brightness.

Question 5: Graphical Interpretation and Calculations (3 Marks)

• Current Identification: Using a V-I graph, determine the current running through Device A and Device B when a voltage of $6.0V$ is applied across them.

• Resistance Calculation: Using the formula $V = I \times R$, calculate the resistance in Ohms for Device A and Device B. Calculations must be shown clearly.

Question 6: Complex Circuit Design (4 Marks)

• Independent Control Design: Draw a circuit containing a power supply and three light globes in parallel. The design must include switches that turn each light on and off independently, plus one master switch that controls all of them simultaneously.

• Practical Application: Discuss two advantages of using the described parallel circuit for living room wiring compared to other circuit types.

Bonus Question: Energy Transformation

This section involves reflecting on household electrical devices. Complete a table for four different electronic devices, ensuring each device transforms energy into a different type for each example (no repetition of energy types).

Section A answers: Multiple Choice Questions

1. c. Rubber

2. c. They all go out.

3. a. An electric current

4. c. Negative to positive

5. d. Voltage applied across the wire.

6. c. Light bulb 1 is brighter than light bulbs 2 and 3, which both have the same brightness.

7. b. $3.0 \, \text{Ω}$

8. a. $R_1 + R_2$

9. a. Diagram A

10. b. The current will decrease.

11. (B) I and IV

12. b. $12 \, \text{V}$

13. b. The charges are the same because the balls are repelling each other.

14. a. The furnace motor, the light bulb, and the exhaust fan only

15. b. $385 \, \text{mA}$

Section B answers: True and False Questions

1. True

2. False

3. True

4. True

5. False

Section C answers: Short Answer Questions

Question 1:

• Circuit Components:
  

  • Power source (battery)

  • Load (e.g., light bulb)

  • Conductive path (wires)

• Standard Symbols:
  

  • Open Switch: ( 🌐 )

  • Voltmeter: ( 🟡 )

  • Battery: ( 🔋 )

  • Light Globe: ( 💡 )

  • Ammeter: ( 📏 )

  • Resistor: ( ⚫ )

• Series and Parallel Analysis:
      i. Circuits A and B are in series.
      ii. Circuit A has the brightest bulbs.
      iii. Circuit C has the dimmest bulbs.

Question 2:

• Connection Methods:
  

  • An ammeter is connected in series, while a voltmeter is connected in parallel.

• Operational Differences:
  

  • An ammeter measures current, while a voltmeter measures voltage.

  • The ammeter has low internal resistance, while the voltmeter has high internal resistance.

• Current and Voltage Comparison:
  

  • Series Circuits: Current behavior: same; Voltage behavior: different.

  • Parallel Circuits: Current behavior: different; Voltage behavior: same.

Question 3:

• Circuit Diagram: (Draw a closed circuit with a bulb and a battery)

• Functional Explanation:
  

  • A torch works by allowing electric current from batteries to flow through a circuit, lighting the bulb when the switch is closed.

• Energy Transformation:
  

  • Chemical energy in the batteries is transformed into electrical energy, which is then converted into light energy by the bulb.

Question 4:

• Switch Scenario Table:
  

  • Switch A: Globe 1: ON, Globe 2: OFF, Globe 3: OFF

  • Switches A, B, C: Globe 1: ON, Globe 2: ON, Globe 3: OFF

  • Switches A, D, E: Globe 1: ON, Globe 2: OFF, Globe 3: OFF

  • Switches A, B, D, E: Globe 1: ON, Globe 2: ON, Globe 3: ON

• Uniform Brightness: To achieve uniform brightness, switches A, B, C must be closed.

Question 5:

• Current Identification: Device A: $0.5 \, \text{A}$, Device B: $0.75 \, \text{A}$

• Resistance Calculation:
  

  • For Device A: $R_A = \frac{V}{I} = \frac{6.0 \, \text{V}}{0.5 \, \text{A}} = 12 \, \text{Ω}$

  • For Device B: $R_B = \frac{V}{I} = \frac{6.0 \, \text{V}}{0.75 \, \text{A}} = 8 \, \text{Ω}$

Question 6:

• Independent Control Design: (Draw the circuit design showing three bulbs in parallel with individual switches)

• Practical Application: Two advantages include:
  

  1. If one bulb fails, others remain lit.

  2. Each light can be controlled independently, saving energy.

Bonus Question answers: Energy Transformation