Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 663 · 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 ON? (a) closed (b) open
2. 2.🔦 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) No (b) Yes
3. 3.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
4. 4.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
5. 5.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
6. 6.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
7. 7.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
8. 8.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
9. 9.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
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) Yes (b) No
11. 11.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a broken path (d) a complete loop
12. 12.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is OFF (c) a wire has come loose (d) all wires are joined
13. 13.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire has come loose (d) all wires are joined
14. 14.🔁 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
15. 15.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
16. 16.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
17. 17.🔦 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) No (b) Yes
18. 18.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a wire is cut (d) the switch is ON
19. 19.🔦 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) Yes (b) No
20. 20.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
21. 21.🔦 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
22. 22.Which of these means the circuit is open? (a) the loop is complete (b) the switch is OFF (c) the switch is ON (d) all wires are joined
23. 23.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a closed circuit (c) a series circuit (d) an open circuit
24. 24.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the filament (d) the glass
25. 25.🔦 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) Yes (b) No
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.🔦 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) No (b) Yes
28. 28.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a cell is taken out (d) all wires are joined
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 steel spoon. Does the bulb glow? (a) No (b) Yes
30. 30.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
31. 31.Which of these means the circuit is closed? (a) the loop is complete (b) a wire has come loose (c) the switch is OFF (d) the bulb is unscrewed
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 paper strip. Does the bulb glow? (a) No (b) Yes
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. Does the bulb glow? (a) Yes (b) No
34. 34.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
35. 35.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
36. 36.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
37. 37.🔦 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
38. 38.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
39. 39.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
40. 40.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) the switch is OFF (d) the switch is ON

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