Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 310 · 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. All the wires are firmly joined. A gap in one wire is bridged by a steel coin. Does the bulb glow? (a) No (b) Yes
2. 2.🔦 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
3. 3.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
4. 4.🔦 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) No (b) Yes
5. 5.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
6. 6.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
7. 7.🔁 What must there be for a current to flow? (a) a complete loop (b) one loose end (c) a plastic gap (d) a broken path
8. 8.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
9. 9.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) the loop is complete (d) a cell is taken out
10. 10.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
11. 11.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
12. 12.Which of these means the circuit is open? (a) the switch is OFF (b) the loop is complete (c) all wires are joined (d) the switch is ON
13. 13.Which of these means the circuit is open? (a) a wire is cut (b) the switch is ON (c) the loop is complete (d) all wires are joined
14. 14.🔦 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
15. 15.🔁 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
16. 16.Which of these means the circuit is closed? (a) all wires are joined (b) the switch is OFF (c) a wire is cut (d) a wire has come loose
17. 17.🔦 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) Yes (b) No
18. 18.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
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 a copper wire. Does the bulb glow? (a) Yes (b) No
20. 20.🔁 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
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 safety pin. Does the bulb glow? (a) No (b) Yes
22. 22.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) a wire has come loose (d) the switch is ON
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 aluminium foil. Does the bulb glow? (a) No (b) Yes
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. Does the bulb glow? (a) No (b) Yes
25. 25.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the bulb is unscrewed (d) the loop is complete
26. 26.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
27. 27.🔦 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
28. 28.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the base (d) the switch
29. 29.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
30. 30.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
31. 31.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
32. 32.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
33. 33.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
34. 34.🔦 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 straw. Does the bulb glow? (a) Yes (b) No
35. 35.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
36. 36.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
37. 37.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a cell is taken out (d) all wires are joined
38. 38.🔦 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
39. 39.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
40. 40.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True

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