Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 341 · 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) the switch is ON (b) a cell is taken out (c) the loop is complete (d) all wires are joined
2. 2.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the bulb is unscrewed
3. 3.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) the bulb is unscrewed (d) the switch is ON
4. 4.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a wire has come loose (d) the switch is ON
5. 5.🔦 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) Yes (b) No
6. 6.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
7. 7.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
8. 8.🔦 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
9. 9.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
10. 10.Which of these means the circuit is open? (a) a wire is cut (b) all wires are joined (c) the switch is ON (d) the loop is complete
11. 11.🔦 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
12. 12.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
13. 13.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
14. 14.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the base (c) the glass (d) the switch
15. 15.🔁 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
16. 16.🔦 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
17. 17.Which of these means the circuit is closed? (a) a wire is cut (b) a wire has come loose (c) all wires are joined (d) the switch is OFF
18. 18.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
19. 19.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
20. 20.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
21. 21.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
22. 22.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
23. 23.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
24. 24.🔦 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
25. 25.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
26. 26.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
27. 27.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
28. 28.Which of these means the circuit is open? (a) the switch is OFF (b) the switch is ON (c) all wires are joined (d) the loop is complete
29. 29.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
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 a glass marble. Does the bulb glow? (a) Yes (b) No
31. 31.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
32. 32.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is OFF (c) the loop is complete (d) a wire has come loose
33. 33.🔦 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) Yes (b) No
34. 34.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
35. 35.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
36. 36.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
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. Does the bulb glow? (a) No (b) Yes
38. 38.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
39. 39.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) none (c) only one (d) it does not matter
40. 40.🔦 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 graphite rod. Does the bulb glow? (a) No (b) Yes

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