Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 7 · 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 cell is taken out? (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 glass (d) the filament
3. 3.Which of these means the circuit is closed? (a) a wire has come loose (b) the loop is complete (c) a wire is cut (d) the switch is OFF
4. 4.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
5. 5.Which of these means the circuit is open? (a) all wires are joined (b) the bulb is unscrewed (c) the switch is ON (d) the loop is complete
6. 6.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
7. 7.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
8. 8.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
9. 9.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
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 glass marble. Does the bulb glow? (a) No (b) Yes
11. 11.Which of these means the circuit is open? (a) a cell is taken out (b) the loop is complete (c) all wires are joined (d) the switch is ON
12. 12.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
13. 13.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire is cut (c) all wires are joined (d) a wire has come loose
14. 14.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
15. 15.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
16. 16.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
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) a wire has come loose
18. 18.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
19. 19.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
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.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
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. 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
24. 24.🔁 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
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 copper wire. 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 plastic ruler. Does the bulb glow? (a) No (b) Yes
27. 27.🔦 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
28. 28.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
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 safety pin. Does the bulb glow? (a) No (b) Yes
30. 30.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
31. 31.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
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. Does the bulb glow? (a) No (b) Yes
33. 33.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
34. 34.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
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 paper strip. Does the bulb glow? (a) Yes (b) No
36. 36.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) the switch is ON (d) a wire has come loose
37. 37.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
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 paper strip. Does the bulb glow? (a) No (b) Yes
39. 39.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) only one (c) it does not matter (d) both of them
40. 40.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True

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