Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 276 · 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.Which of these means the circuit is closed? (a) a cell is taken out (b) all wires are joined (c) a wire has come loose (d) a wire is cut
3. 3.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
4. 4.🔦 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) No (b) Yes
5. 5.Which of these means the circuit is open? (a) a cell is taken out (b) the switch is ON (c) all wires are joined (d) the loop is complete
6. 6.🔦 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 rubber eraser. Does the bulb glow? (a) Yes (b) No
7. 7.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
8. 8.🔦 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
9. 9.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) the switch is ON (d) a cell is taken out
10. 10.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
11. 11.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a full circuit (c) a series circuit (d) a closed circuit
12. 12.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
13. 13.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
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 switch is OFF (c) the loop is complete (d) all wires are joined
16. 16.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) none (c) it does not matter (d) only one
17. 17.🔦 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
18. 18.Which of these means the circuit is open? (a) the switch is ON (b) a wire is cut (c) the loop is complete (d) all wires are joined
19. 19.🔦 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
20. 20.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
21. 21.🔦 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) Yes (b) No
22. 22.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the base (d) the switch
23. 23.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
24. 24.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
25. 25.🔦 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 ruler. Does the bulb glow? (a) No (b) Yes
26. 26.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
27. 27.🔦 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
28. 28.🔦 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 paper strip. Does the bulb glow? (a) Yes (b) No
29. 29.🔦 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) Yes (b) No
30. 30.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the loop is complete (d) the switch is ON
31. 31.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
32. 32.Which of these means the circuit is closed? (a) a wire is cut (b) the loop is complete (c) a cell is taken out (d) a wire has come loose
33. 33.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
34. 34.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
35. 35.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
36. 36.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
37. 37.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
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 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
40. 40.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is ON (d) all wires are joined

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