Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 496 · 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.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
2. 2.🔦 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
3. 3.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
4. 4.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) only one (c) both of them (d) none
5. 5.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
6. 6.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
7. 7.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
8. 8.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) one loose end (d) a complete loop
9. 9.Which of these means the circuit is open? (a) all wires are joined (b) a wire has come loose (c) the switch is ON (d) the loop is complete
10. 10.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
11. 11.🔦 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
12. 12.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
13. 13.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
14. 14.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
15. 15.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the glass (d) the base
16. 16.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a full circuit (d) a series circuit
17. 17.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) the loop is complete (d) the switch is OFF
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) Yes (b) No
19. 19.Which of these means the circuit is closed? (a) the switch is OFF (b) the switch is ON (c) a cell is taken out (d) a wire is cut
20. 20.🔦 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
21. 21.Which of these means the circuit is open? (a) the loop is complete (b) a cell is taken out (c) all wires are joined (d) the switch is ON
22. 22.Which of these means the circuit is open? (a) the switch is ON (b) the switch is OFF (c) the loop is complete (d) all wires are joined
23. 23.🔦 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) Yes (b) No
24. 24.Which of these means the circuit is closed? (a) all wires are joined (b) the bulb is unscrewed (c) a cell is taken out (d) the switch is OFF
25. 25.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
26. 26.🔦 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) Yes (b) No
27. 27.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
28. 28.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
29. 29.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
30. 30.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a wire is cut (d) the switch is ON
31. 31.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) the bulb is unscrewed
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 copper wire. Does the bulb glow? (a) Yes (b) No
33. 33.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
34. 34.🔦 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
35. 35.🔦 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 rubber band. Does the bulb glow? (a) No (b) Yes
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 aluminium foil. Does the bulb glow? (a) No (b) Yes
37. 37.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
38. 38.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
39. 39.🔦 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
40. 40.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No

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