Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 322 · 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.Which of these means the circuit is open? (a) a cell is taken out (b) the loop is complete (c) the switch is ON (d) all wires are joined
2. 2.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
3. 3.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) a series circuit (d) an open circuit
4. 4.🔦 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
5. 5.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
6. 6.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
7. 7.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
8. 8.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
9. 9.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
10. 10.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
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 plastic straw. Does the bulb glow? (a) Yes (b) No
12. 12.🔦 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
13. 13.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the base (c) the glass (d) the switch
14. 14.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
15. 15.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
16. 16.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
17. 17.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
18. 18.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
19. 19.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
20. 20.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a cell is taken out (c) the switch is OFF (d) the loop is complete
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 an iron nail. Does the bulb glow? (a) Yes (b) No
22. 22.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a wire is cut
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 glass marble. Does the bulb glow? (a) No (b) Yes
24. 24.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
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 a rubber band. Does the bulb glow? (a) Yes (b) No
26. 26.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
27. 27.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) the switch is ON (d) the switch is OFF
28. 28.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
29. 29.🔦 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
30. 30.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
31. 31.🔦 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
32. 32.🔦 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
33. 33.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
34. 34.🔁 What must there be for a current to flow? (a) a complete loop (b) one loose end (c) a broken path (d) a plastic gap
35. 35.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the switch is OFF (d) the loop is complete
36. 36.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a wire has come loose (d) the loop is complete
37. 37.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
38. 38.Which of these means the circuit is closed? (a) a cell is taken out (b) all wires are joined (c) the bulb is unscrewed (d) a wire has come loose
39. 39.🔁 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) only one (d) none
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 aluminium foil. Does the bulb glow? (a) No (b) Yes

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