Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 963 · 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) one loose end (c) a plastic gap (d) a complete loop
2. 2.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
3. 3.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
4. 4.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
5. 5.🔦 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
6. 6.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the switch is ON (c) all wires are joined (d) the loop is complete
7. 7.🔦 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
8. 8.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
9. 9.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the base (d) the glass
10. 10.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
11. 11.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
12. 12.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
13. 13.🔦 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 graphite rod. Does the bulb glow? (a) No (b) Yes
14. 14.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
15. 15.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
16. 16.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
17. 17.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a cell is taken out (d) the loop is complete
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
19. 19.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
20. 20.🔦 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
21. 21.🔦 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
22. 22.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) both of them (c) none (d) only one
23. 23.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
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. A gap in one wire is bridged by a glass marble. Does the bulb glow? (a) Yes (b) No
25. 25.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
26. 26.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) a wire is cut (d) the switch is ON
27. 27.🔦 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 eraser. 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 copper wire. Does the bulb glow? (a) No (b) Yes
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 steel spoon. Does the bulb glow? (a) Yes (b) No
30. 30.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
31. 31.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
32. 32.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
33. 33.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) the switch is OFF
34. 34.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a wire has come loose (d) the loop is complete
35. 35.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
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 rubber band. Does the bulb glow? (a) No (b) Yes
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 cotton thread. Does the bulb glow? (a) Yes (b) No
38. 38.🔁 Is the circuit closed or open if the loop is complete? (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.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False

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