Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 943 · 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.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) a wire has come loose (d) all wires are joined
2. 2.🔦 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
3. 3.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
4. 4.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the glass (d) the filament
5. 5.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) it does not matter (c) none (d) only one
6. 6.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
7. 7.🔦 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
8. 8.Which of these means the circuit is closed? (a) the loop is complete (b) the bulb is unscrewed (c) the switch is OFF (d) a wire is cut
9. 9.Which of these means the circuit is open? (a) a cell is taken out (b) all wires are joined (c) the switch is ON (d) the loop is complete
10. 10.🔦 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
11. 11.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is ON (c) a wire has come loose (d) a wire is cut
12. 12.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
13. 13.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
14. 14.🔦 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
15. 15.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
16. 16.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
17. 17.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
18. 18.🔦 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
19. 19.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a series circuit (c) a closed circuit (d) a full circuit
20. 20.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
21. 21.🔦 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 straw. Does the bulb glow? (a) Yes (b) No
22. 22.🔦 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) No (b) Yes
23. 23.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
24. 24.🔦 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) Yes (b) No
25. 25.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a wire has come loose (d) the switch is ON
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) No (b) Yes
27. 27.🔦 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
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 steel coin. 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. 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
30. 30.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
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 graphite rod. Does the bulb glow? (a) No (b) Yes
32. 32.🔦 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) Yes (b) No
33. 33.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
34. 34.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
35. 35.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
36. 36.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) all wires are joined (d) the switch is ON
37. 37.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
38. 38.🔦 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) Yes (b) No
39. 39.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
40. 40.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes

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