Electronics Worksheet: Simple Circuit – Open and Closed

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

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