Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 872 · 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 a wire is cut? (a) closed (b) open
2. 2.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the filament (d) the glass
3. 3.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) the bulb is unscrewed (d) all wires are joined
4. 4.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
5. 5.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
6. 6.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the switch is OFF (d) the loop is complete
7. 7.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a full circuit (c) a closed circuit (d) a series circuit
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 steel spoon. Does the bulb glow? (a) No (b) Yes
9. 9.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
10. 10.🔦 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
11. 11.🔦 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
12. 12.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the switch is ON (d) the loop is complete
13. 13.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) both of them (c) none (d) it does not matter
14. 14.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
15. 15.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
16. 16.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire has come loose (c) a wire is cut (d) all wires are joined
17. 17.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
18. 18.🔦 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
19. 19.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
20. 20.Which of these means the circuit is closed? (a) the switch is ON (b) a wire is cut (c) a cell is taken out (d) a wire has come loose
21. 21.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
22. 22.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
23. 23.🔦 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 band. Does the bulb glow? (a) No (b) Yes
24. 24.Which of these means the circuit is closed? (a) the loop is complete (b) a wire has come loose (c) the bulb is unscrewed (d) the switch is OFF
25. 25.🔦 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
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 copper wire. Does the bulb glow? (a) No (b) Yes
27. 27.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
28. 28.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
29. 29.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
30. 30.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
31. 31.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
32. 32.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
33. 33.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
34. 34.🔦 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 coin. Does the bulb glow? (a) Yes (b) No
35. 35.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
36. 36.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
37. 37.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 is cut
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 wooden stick. Does the bulb glow? (a) Yes (b) No
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 safety pin. Does the bulb glow? (a) Yes (b) No
40. 40.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True

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