Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 803 · 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.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
2. 2.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 wire is cut
3. 3.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a wire has come loose
4. 4.🔁 What must there be for a current to flow? (a) a plastic gap (b) a complete loop (c) a broken path (d) one loose end
5. 5.Which of these means the circuit is closed? (a) a wire has come loose (b) the loop is complete (c) the bulb is unscrewed (d) a cell is taken out
6. 6.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
7. 7.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
8. 8.🔦 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
9. 9.🔦 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) Yes (b) No
10. 10.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
11. 11.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
12. 12.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) only one (c) none (d) it does not matter
13. 13.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
14. 14.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
15. 15.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the switch (d) the filament
16. 16.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
17. 17.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
18. 18.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
19. 19.Which of these means the circuit is open? (a) the switch is OFF (b) the switch is ON (c) all wires are joined (d) the loop is complete
20. 20.🔦 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
21. 21.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) an open circuit (c) a full circuit (d) a closed circuit
22. 22.Which of these means the circuit is closed? (a) all wires are joined (b) the switch is OFF (c) the bulb is unscrewed (d) a wire has come loose
23. 23.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
24. 24.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) the switch is ON (d) the bulb is unscrewed
25. 25.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
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. A gap in one wire is bridged by a ceramic cup. Does the bulb glow? (a) Yes (b) No
27. 27.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
28. 28.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
29. 29.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
30. 30.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
31. 31.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
32. 32.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
33. 33.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
34. 34.🔦 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 rubber eraser. Does the bulb glow? (a) No (b) Yes
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 a metal paper clip. Does the bulb glow? (a) No (b) Yes
36. 36.🔦 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
37. 37.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
38. 38.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
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) Yes (b) No
40. 40.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False

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