Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 382 · 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 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
2. 2.🔁 What must there be for a current to flow? (a) a broken path (b) one loose end (c) a complete loop (d) a plastic gap
3. 3.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
4. 4.🔦 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) No (b) Yes
5. 5.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
6. 6.Which of these means the circuit is open? (a) the bulb is unscrewed (b) all wires are joined (c) the switch is ON (d) the loop is complete
7. 7.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
8. 8.🔦 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
9. 9.Which of these means the circuit is closed? (a) a wire is cut (b) a cell is taken out (c) all wires are joined (d) a wire has come loose
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 paper strip. 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.🔦 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
13. 13.🔦 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 paper strip. Does the bulb glow? (a) Yes (b) No
14. 14.Which of these means the circuit is open? (a) the switch is ON (b) a wire is cut (c) the loop is complete (d) all wires are joined
15. 15.🔦 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 steel spoon. Does the bulb glow? (a) No (b) Yes
16. 16.🔦 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 wooden stick. Does the bulb glow? (a) No (b) Yes
17. 17.🔦 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 steel spoon. Does the bulb glow? (a) No (b) Yes
18. 18.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
19. 19.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
20. 20.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a series circuit (d) a full circuit
21. 21.🔦 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
22. 22.🔦 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) Yes (b) No
23. 23.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
24. 24.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
25. 25.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
26. 26.🔦 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 coin. Does the bulb glow? (a) Yes (b) No
27. 27.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the base (d) the glass
28. 28.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
29. 29.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
30. 30.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
31. 31.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
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) Yes (b) No
33. 33.Which of these means the circuit is closed? (a) the switch is ON (b) a wire is cut (c) the switch is OFF (d) a wire has come loose
34. 34.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
35. 35.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
36. 36.🔦 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) Yes (b) No
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.🔦 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) No (b) Yes
39. 39.Which of these means the circuit is open? (a) the switch is ON (b) the switch is OFF (c) the loop is complete (d) all wires are joined
40. 40.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a cell is taken out (d) all wires are joined

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