Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 343 · 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) a wire has come loose (c) the switch is OFF (d) the loop is complete
2. 2.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
3. 3.🔦 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 plastic ruler. Does the bulb glow? (a) No (b) Yes
4. 4.🔦 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
5. 5.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) it does not matter (d) both of them
6. 6.🔦 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
7. 7.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
8. 8.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is ON (c) a wire has come loose (d) the bulb is unscrewed
9. 9.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
10. 10.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a cell is taken out (d) the switch is ON
11. 11.Which of these means the circuit is open? (a) all wires are joined (b) a wire is cut (c) the loop is complete (d) the switch is ON
12. 12.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
13. 13.🔁 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
14. 14.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
15. 15.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
16. 16.🔦 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) No (b) Yes
17. 17.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
18. 18.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the switch (d) the filament
19. 19.🔦 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
20. 20.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
21. 21.🔁 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
22. 22.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
23. 23.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
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 steel coin. Does the bulb glow? (a) No (b) Yes
25. 25.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) the bulb is unscrewed (d) all wires are joined
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 brass key. Does the bulb glow? (a) No (b) Yes
27. 27.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
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 dry cork. Does the bulb glow? (a) No (b) Yes
29. 29.🔁 Is the circuit closed or open if the switch is OFF? (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 safety pin. Does the bulb glow? (a) No (b) Yes
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 copper wire. Does the bulb glow? (a) No (b) Yes
32. 32.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
33. 33.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
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. A gap in one wire is bridged by a steel coin. Does the bulb glow? (a) Yes (b) No
35. 35.🔦 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
36. 36.🔦 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
37. 37.Which of these means the circuit is open? (a) the switch is ON (b) a wire has come loose (c) all wires are joined (d) the loop is complete
38. 38.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
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 rubber band. Does the bulb glow? (a) No (b) Yes
40. 40.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False

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