Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 625 · 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.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
2. 2.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
3. 3.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) only one (c) none (d) both of them
4. 4.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
5. 5.🔦 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
6. 6.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) a full circuit (d) an open circuit
7. 7.🔦 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
8. 8.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
9. 9.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) the switch is ON (d) a cell is taken out
10. 10.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
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) No (b) Yes
12. 12.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
13. 13.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
14. 14.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
15. 15.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a wire has come loose (d) all wires are joined
16. 16.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
17. 17.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
18. 18.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
19. 19.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a broken path (d) a plastic gap
20. 20.🔦 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
21. 21.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the switch (d) the base
22. 22.🔦 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 plastic ruler. Does the bulb glow? (a) Yes (b) No
23. 23.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) the bulb is unscrewed (d) all wires are joined
24. 24.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) the bulb is unscrewed (d) all wires are joined
25. 25.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
26. 26.🔦 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
27. 27.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
28. 28.Which of these means the circuit is open? (a) all wires are joined (b) a cell is taken out (c) the switch is ON (d) the loop is complete
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 glass marble. Does the bulb glow? (a) No (b) Yes
30. 30.🔦 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 rubber band. Does the bulb glow? (a) No (b) Yes
31. 31.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
32. 32.🔦 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 a steel coin. Does the bulb glow? (a) No (b) Yes
33. 33.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
34. 34.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
35. 35.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
36. 36.🔦 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
37. 37.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) a wire is cut (d) the loop is complete
38. 38.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
39. 39.🔦 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 a plastic straw. Does the bulb glow? (a) No (b) Yes
40. 40.Which of these means the circuit is open? (a) the switch is OFF (b) the switch is ON (c) the loop is complete (d) all wires are joined

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