Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 320 · 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.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) a complete loop (d) one loose end
2. 2.🔦 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
3. 3.Which of these means the circuit is open? (a) the loop is complete (b) a wire has come loose (c) all wires are joined (d) the switch is ON
4. 4.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
5. 5.🔦 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) Yes (b) No
6. 6.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) a wire is cut
7. 7.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
8. 8.🔦 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
9. 9.Which of these means the circuit is closed? (a) all wires are joined (b) a wire is cut (c) the switch is OFF (d) the bulb is unscrewed
10. 10.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire has come loose (c) the switch is ON (d) the switch is OFF
11. 11.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
12. 12.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
13. 13.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
14. 14.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
15. 15.🔦 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 metal paper clip. 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 an iron nail. Does the bulb glow? (a) No (b) Yes
17. 17.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
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 graphite rod. Does the bulb glow? (a) No (b) Yes
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
20. 20.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
21. 21.🔁 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
22. 22.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 bulb is unscrewed
23. 23.🔦 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
24. 24.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) it does not matter (c) only one (d) none
25. 25.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
26. 26.Which of these means the circuit is open? (a) the switch is OFF (b) all wires are joined (c) the loop is complete (d) the switch is ON
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 a steel spoon. Does the bulb glow? (a) No (b) Yes
28. 28.🔦 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 rubber eraser. Does the bulb glow? (a) Yes (b) No
29. 29.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
30. 30.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the glass (d) the base
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 a rubber band. Does the bulb glow? (a) Yes (b) No
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 graphite rod. Does the bulb glow? (a) Yes (b) No
33. 33.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
34. 34.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
35. 35.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
36. 36.🔦 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
37. 37.🔦 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
38. 38.Which of these means the circuit is closed? (a) the loop is complete (b) a wire is cut (c) a wire has come loose (d) the switch is OFF
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 paper strip. Does the bulb glow? (a) No (b) Yes
40. 40.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True

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