Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 823 · 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) open (b) closed
2. 2.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
3. 3.🔦 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
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 an iron nail. Does the bulb glow? (a) Yes (b) No
5. 5.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) the switch is OFF (d) all wires are joined
6. 6.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
7. 7.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) all wires are joined (c) the switch is OFF (d) a cell is taken out
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 glass marble. Does the bulb glow? (a) Yes (b) No
9. 9.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is ON (c) the bulb is unscrewed (d) a wire has come loose
10. 10.🔁 What must there be for a current to flow? (a) a complete loop (b) one loose end (c) a broken path (d) a plastic gap
11. 11.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
12. 12.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
13. 13.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
14. 14.🔦 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
15. 15.🔦 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 rubber eraser. Does the bulb glow? (a) Yes (b) No
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. Does the bulb glow? (a) Yes (b) No
17. 17.Which of these means the circuit is open? (a) the switch is ON (b) a wire has come loose (c) all wires are joined (d) the loop is complete
18. 18.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
19. 19.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) only one (d) both of them
20. 20.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
21. 21.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) an open circuit (c) a full circuit (d) a closed circuit
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 plastic ruler. Does the bulb glow? (a) Yes (b) No
23. 23.🔦 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) Yes (b) No
24. 24.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the base (c) the switch (d) the glass
25. 25.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
26. 26.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
27. 27.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
28. 28.True or false: if all wires are joined, 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 dry cork. Does the bulb glow? (a) No (b) Yes
30. 30.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
31. 31.🔦 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
32. 32.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
33. 33.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
34. 34.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
35. 35.True or false: if the switch is OFF, 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 paper strip. Does the bulb glow? (a) Yes (b) No
37. 37.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
38. 38.Which of these means the circuit is closed? (a) the switch is OFF (b) the loop is complete (c) the bulb is unscrewed (d) a wire has come loose
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 ceramic cup. Does the bulb glow? (a) Yes (b) No
40. 40.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a cell is taken out (d) the loop is complete

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