Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 424 · 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 ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
2. 2.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a series circuit (d) a full circuit
3. 3.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
4. 4.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
5. 5.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a wire is cut (d) the switch is ON
6. 6.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) one loose end (d) a plastic gap
7. 7.True or false: if the switch is ON, the circuit is open and no 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. A gap in one wire is bridged by a woollen thread. Does the bulb glow? (a) Yes (b) No
9. 9.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) only one (d) both of them
10. 10.Which of these means the circuit is closed? (a) the switch is OFF (b) the switch is ON (c) a wire has come loose (d) the bulb is unscrewed
11. 11.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
12. 12.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
13. 13.🔦 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
14. 14.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
15. 15.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a cell is taken out (c) the loop is complete (d) a wire has come loose
16. 16.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
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 a safety pin. Does the bulb glow? (a) Yes (b) No
18. 18.🔦 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
19. 19.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
20. 20.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
21. 21.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
22. 22.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
23. 23.Which of these means the circuit is open? (a) a cell is taken out (b) all wires are joined (c) the loop is complete (d) the switch is ON
24. 24.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
25. 25.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
26. 26.🔦 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
27. 27.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
28. 28.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
29. 29.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
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 steel coin. Does the bulb glow? (a) No (b) Yes
31. 31.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
32. 32.🔦 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
33. 33.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
34. 34.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
35. 35.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the glass (c) the switch (d) the filament
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.True or false: if the bulb is unscrewed, the circuit is closed and 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 a metal paper clip. Does the bulb glow? (a) No (b) Yes
39. 39.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
40. 40.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed

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