Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 184 · 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 OFF? (a) closed (b) open
2. 2.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
3. 3.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a plastic gap (d) a complete loop
4. 4.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) the loop is complete (d) the bulb is unscrewed
5. 5.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) the switch is OFF (d) all wires are joined
6. 6.🔁 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
7. 7.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
8. 8.🔦 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
9. 9.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
10. 10.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
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 cotton thread. Does the bulb glow? (a) Yes (b) No
12. 12.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
13. 13.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) an open circuit (d) a full circuit
14. 14.🔦 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
15. 15.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) a wire is cut (d) the switch is ON
16. 16.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
17. 17.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) the switch is OFF
18. 18.True or false: if a wire is cut, the circuit is closed and 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. Does the bulb glow? (a) No (b) Yes
20. 20.🔦 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) No (b) Yes
21. 21.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a cell is taken out (d) the loop is complete
22. 22.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) a wire has come loose
23. 23.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
24. 24.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
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 plastic ruler. Does the bulb glow? (a) Yes (b) No
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 brass key. Does the bulb glow? (a) Yes (b) No
27. 27.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
28. 28.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
29. 29.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the bulb is unscrewed (d) the loop is complete
30. 30.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
31. 31.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
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 cotton thread. Does the bulb glow? (a) No (b) Yes
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 copper wire. Does the bulb glow? (a) No (b) Yes
34. 34.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
35. 35.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the base (c) the glass (d) the switch
36. 36.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
37. 37.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
38. 38.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
39. 39.🔦 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 metal paper clip. 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 rubber eraser. Does the bulb glow? (a) No (b) Yes

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