Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 59 · 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 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
2. 2.Which of these means the circuit is closed? (a) a wire is cut (b) all wires are joined (c) a cell is taken out (d) the switch is OFF
3. 3.True or false: if the loop is complete, 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) Yes (b) No
5. 5.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the switch is OFF (d) the loop is complete
6. 6.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
7. 7.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
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 rubber eraser. Does the bulb glow? (a) Yes (b) No
9. 9.Which of these means the circuit is closed? (a) the switch is ON (b) the switch is OFF (c) a wire is cut (d) a wire has come loose
10. 10.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) none (c) both of them (d) only one
11. 11.🔦 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
12. 12.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a series circuit (d) a closed circuit
13. 13.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) a wire has come loose (d) the loop is complete
14. 14.🔦 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
15. 15.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
16. 16.🔁 What must there be for a current to flow? (a) a plastic gap (b) one loose end (c) a complete loop (d) a broken path
17. 17.🔦 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) Yes (b) No
18. 18.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
19. 19.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
20. 20.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
21. 21.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
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.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a cell is taken out (d) all wires are joined
24. 24.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
25. 25.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
26. 26.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
27. 27.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
28. 28.🔦 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
29. 29.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
30. 30.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a wire is cut (d) the switch is ON
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 wooden stick. Does the bulb glow? (a) No (b) Yes
32. 32.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
33. 33.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
34. 34.🔦 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 brass key. 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 glass marble. Does the bulb glow? (a) Yes (b) No
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
37. 37.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
38. 38.🔦 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
39. 39.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
40. 40.🔦 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

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