Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 737 · 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 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
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. A gap in one wire is bridged by a steel spoon. Does the bulb glow? (a) Yes (b) No
3. 3.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
4. 4.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) a cell is taken out
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 rubber band. Does the bulb glow? (a) Yes (b) No
6. 6.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a full circuit (d) a series circuit
7. 7.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
8. 8.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
9. 9.Which of these means the circuit is closed? (a) a wire is cut (b) a wire has come loose (c) the loop is complete (d) a cell is taken out
10. 10.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
11. 11.🔦 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) Yes (b) No
12. 12.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
13. 13.🔁 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
14. 14.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
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 cotton thread. Does the bulb glow? (a) No (b) Yes
16. 16.Which of these means the circuit is closed? (a) the switch is ON (b) a wire has come loose (c) the switch is OFF (d) a wire is cut
17. 17.🔦 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
18. 18.🔦 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
19. 19.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
20. 20.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
21. 21.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
22. 22.🔦 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
23. 23.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
24. 24.Which of these means the circuit is open? (a) a wire is cut (b) the switch is ON (c) all wires are joined (d) the loop is complete
25. 25.🔦 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
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 copper wire. Does the bulb glow? (a) Yes (b) No
27. 27.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
28. 28.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) the bulb is unscrewed
29. 29.🔦 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
30. 30.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the switch (d) the filament
31. 31.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
32. 32.🔦 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
33. 33.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
34. 34.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
35. 35.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
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 a woollen thread. Does the bulb glow? (a) No (b) Yes
37. 37.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
38. 38.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
39. 39.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
40. 40.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) the bulb is unscrewed (d) all wires are joined

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