Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 882 · 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 all wires are joined? (a) open (b) closed
2. 2.🔦 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
3. 3.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) an open circuit (d) a full circuit
4. 4.🔦 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
5. 5.🔦 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
6. 6.🔦 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) No (b) Yes
7. 7.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
8. 8.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
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.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) a wire has come loose (d) the switch is ON
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 plastic ruler. Does the bulb glow? (a) No (b) Yes
12. 12.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
13. 13.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
14. 14.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
15. 15.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
16. 16.🔦 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) Yes (b) No
17. 17.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
18. 18.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
19. 19.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) the loop is complete (d) the bulb is unscrewed
20. 20.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
21. 21.Which of these means the circuit is open? (a) the switch is OFF (b) all wires are joined (c) the switch is ON (d) the loop is complete
22. 22.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
23. 23.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
24. 24.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
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 safety pin. Does the bulb glow? (a) Yes (b) No
26. 26.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
27. 27.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
28. 28.🔦 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 plastic ruler. Does the bulb glow? (a) No (b) Yes
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 metal paper clip. Does the bulb glow? (a) Yes (b) No
30. 30.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) all wires are joined (d) the switch is ON
31. 31.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
32. 32.Which of these means the circuit is open? (a) a cell is taken out (b) the switch is ON (c) the loop is complete (d) all wires are joined
33. 33.🔦 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
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. Does the bulb glow? (a) No (b) Yes
35. 35.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the switch (d) the glass
36. 36.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
37. 37.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
39. 39.🔦 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 plastic straw. Does the bulb glow? (a) Yes (b) No
40. 40.🔦 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

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids