Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 224 · 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. Does the bulb glow? (a) Yes (b) No
2. 2.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) only one (d) it does not matter
3. 3.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) all wires are joined (d) the bulb is unscrewed
4. 4.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
5. 5.🔦 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 steel spoon. Does the bulb glow? (a) Yes (b) No
6. 6.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
7. 7.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
8. 8.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
9. 9.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) one loose end (d) a plastic gap
10. 10.🔦 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
11. 11.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
12. 12.Which of these means the circuit is closed? (a) the switch is OFF (b) the loop is complete (c) a wire has come loose (d) a cell is taken out
13. 13.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
14. 14.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) a closed circuit (d) an open circuit
15. 15.🔦 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 eraser. Does the bulb glow? (a) No (b) Yes
16. 16.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
17. 17.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
18. 18.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
19. 19.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
20. 20.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
21. 21.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
22. 22.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
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 rubber band. Does the bulb glow? (a) Yes (b) No
24. 24.🔦 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
25. 25.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
26. 26.🔦 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) No (b) Yes
27. 27.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the switch (d) the base
28. 28.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
29. 29.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
30. 30.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the bulb is unscrewed (d) the switch is ON
31. 31.🔦 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
32. 32.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
33. 33.🔦 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
34. 34.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
35. 35.🔦 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 rubber band. Does the bulb glow? (a) Yes (b) No
36. 36.Which of these means the circuit is open? (a) the loop is complete (b) a cell is taken out (c) all wires are joined (d) the switch is ON
37. 37.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
38. 38.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
39. 39.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
40. 40.Which of these means the circuit is closed? (a) the switch is ON (b) the switch is OFF (c) a wire is cut (d) a wire has come loose

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