Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 453 · 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 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
2. 2.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
3. 3.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
4. 4.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the base (d) the switch
5. 5.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) an open circuit (d) a closed circuit
6. 6.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
7. 7.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
8. 8.Which of these means the circuit is closed? (a) all wires are joined (b) a wire has come loose (c) a cell is taken out (d) the switch is OFF
9. 9.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
10. 10.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
11. 11.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
12. 12.🔦 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 straw. Does the bulb glow? (a) No (b) Yes
13. 13.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
14. 14.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
15. 15.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
16. 16.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
17. 17.🔦 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) No (b) Yes
18. 18.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is ON (d) all wires are joined
19. 19.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
20. 20.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
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 dry cork. Does the bulb glow? (a) No (b) Yes
22. 22.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) the switch is OFF
23. 23.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) a cell is taken out (d) the loop is complete
24. 24.🔦 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) No (b) Yes
25. 25.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) a wire is cut
26. 26.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes
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 wooden stick. Does the bulb glow? (a) No (b) Yes
28. 28.Which of these means the circuit is closed? (a) a wire is cut (b) a cell is taken out (c) the switch is ON (d) a wire has come loose
29. 29.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
30. 30.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
31. 31.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
32. 32.🔦 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) No (b) Yes
33. 33.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) a complete loop (d) one loose end
34. 34.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
35. 35.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
36. 36.🔁 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) none (d) only one
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 wooden stick. Does the bulb glow? (a) Yes (b) No
38. 38.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
39. 39.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
40. 40.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes

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