Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 589 · 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.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
2. 2.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
3. 3.🔦 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
4. 4.🔦 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) No (b) Yes
5. 5.🔦 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
6. 6.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
7. 7.Which of these means the circuit is closed? (a) a cell is taken out (b) the loop is complete (c) the bulb is unscrewed (d) the switch is OFF
8. 8.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
9. 9.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
10. 10.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
11. 11.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a full circuit (c) an open circuit (d) a closed circuit
12. 12.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a cell is taken out (d) the switch is ON
13. 13.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) all wires are joined (d) a wire is cut
14. 14.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
15. 15.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
16. 16.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
17. 17.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) only one (d) both of them
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. Does the bulb glow? (a) No (b) Yes
19. 19.🔁 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
20. 20.🔦 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
21. 21.Which of these means the circuit is closed? (a) the switch is ON (b) a cell is taken out (c) the switch is OFF (d) the bulb is unscrewed
22. 22.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
23. 23.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
24. 24.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
25. 25.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
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 an iron nail. Does the bulb glow? (a) Yes (b) No
27. 27.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
28. 28.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
29. 29.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
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 aluminium foil. Does the bulb glow? (a) No (b) Yes
31. 31.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
32. 32.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
33. 33.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
34. 34.🔦 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
35. 35.🔦 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
36. 36.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) the switch is OFF (d) all wires are joined
37. 37.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
38. 38.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the base (d) the glass
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 plastic ruler. Does the bulb glow? (a) Yes (b) No
40. 40.🔦 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

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