Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 128 · 40 questions

Remember (Follow the loop): Closed circuit = complete loop = current flows; open circuit = a break = no current. Check every part: live cell, good bulb, switch ON, all wires joined, any gap bridged by a conductor. If even one check fails, the bulb does not glow.

1. 1.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
2. 2.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is ON (c) a wire is cut (d) the switch is OFF
3. 3.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
4. 4.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
5. 5.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
6. 6.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) a cell is taken out
7. 7.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
8. 8.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the glass (c) the filament (d) the switch
9. 9.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
10. 10.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
11. 11.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a dry cork. Does the bulb glow? (a) Yes (b) No
12. 12.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
13. 13.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) No (b) Yes
14. 14.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
15. 15.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire has come loose (d) all wires are joined
16. 16.Which of these means the circuit is open? (a) all wires are joined (b) the bulb is unscrewed (c) the switch is ON (d) the loop is complete
17. 17.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) a wire is cut (d) the loop is complete
18. 18.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
19. 19.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a wooden stick. Does the bulb glow? (a) No (b) Yes
20. 20.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
21. 21.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) Yes (b) No
22. 22.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by aluminium foil. Does the bulb glow? (a) Yes (b) No
23. 23.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by aluminium foil. Does the bulb glow? (a) No (b) Yes
24. 24.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
25. 25.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) none (d) both of them
26. 26.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
27. 27.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a wooden stick. Does the bulb glow? (a) Yes (b) No
28. 28.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
29. 29.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a steel coin. Does the bulb glow? (a) Yes (b) No
30. 30.Which of these means the circuit is closed? (a) the switch is OFF (b) all wires are joined (c) the bulb is unscrewed (d) a cell is taken out
31. 31.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) Yes (b) No
32. 32.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
33. 33.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by aluminium foil. Does the bulb glow? (a) Yes (b) No
34. 34.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
35. 35.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
36. 36.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
37. 37.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) a complete loop (d) one loose end
38. 38.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
39. 39.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. A gap in one wire is bridged by a cotton thread. Does the bulb glow? (a) No (b) Yes
40. 40.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a wire is cut (d) the loop is complete

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