Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 193 · 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) open (b) closed
2. 2.🔦 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 plastic ruler. Does the bulb glow? (a) Yes (b) No
3. 3.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
4. 4.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
5. 5.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
6. 6.🔦 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
7. 7.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
8. 8.Which of these means the circuit is closed? (a) all wires are joined (b) a wire is cut (c) a wire has come loose (d) a cell is taken out
9. 9.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a closed circuit (d) a series circuit
10. 10.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) both of them (d) none
11. 11.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
12. 12.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the glass (c) the filament (d) the switch
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 dry cork. Does the bulb glow? (a) Yes (b) No
14. 14.Which of these means the circuit is closed? (a) the loop is complete (b) a cell is taken out (c) a wire has come loose (d) the bulb is unscrewed
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
16. 16.🔦 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 ruler. Does the bulb glow? (a) Yes (b) No
17. 17.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
18. 18.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
19. 19.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
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 a cell is taken out, the circuit is open and no current flows. (a) False (b) True
22. 22.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
23. 23.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
24. 24.🔦 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) Yes (b) No
25. 25.🔦 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 steel spoon. Does the bulb glow? (a) No (b) Yes
26. 26.🔦 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
27. 27.🔦 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
28. 28.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) the switch is OFF
29. 29.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
30. 30.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) the bulb is unscrewed (d) all wires are joined
31. 31.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
32. 32.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
33. 33.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
34. 34.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
35. 35.🔁 What must there be for a current to flow? (a) a broken path (b) one loose end (c) a plastic gap (d) a complete loop
36. 36.🔦 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
37. 37.🔦 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
38. 38.Which of these means the circuit is open? (a) the switch is ON (b) a wire has come loose (c) the loop is complete (d) all wires are joined
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 a steel coin. Does the bulb glow? (a) Yes (b) No
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 cotton thread. Does the bulb glow? (a) Yes (b) No

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