Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 102 · 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.Which of these means the circuit is closed? (a) the switch is OFF (b) the switch is ON (c) a cell is taken out (d) a wire is cut
2. 2.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a full circuit (c) a closed circuit (d) an open circuit
3. 3.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
4. 4.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
5. 5.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
6. 6.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
7. 7.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
8. 8.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
9. 9.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
10. 10.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
11. 11.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) a complete loop (d) one loose end
12. 12.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
13. 13.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
14. 14.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) it does not matter (d) both of them
15. 15.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a wire is cut (d) all wires are joined
16. 16.Which of these means the circuit is closed? (a) all wires are joined (b) the bulb is unscrewed (c) a cell is taken out (d) a wire has come loose
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 brass key. Does the bulb glow? (a) Yes (b) No
18. 18.🔦 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 wooden stick. Does the bulb glow? (a) No (b) Yes
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. A gap in one wire is bridged by a metal paper clip. Does the bulb glow? (a) Yes (b) No
20. 20.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
21. 21.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) the bulb is unscrewed
22. 22.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
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.🔦 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
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 woollen thread. Does the bulb glow? (a) No (b) Yes
26. 26.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 cell is taken out
27. 27.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
28. 28.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
29. 29.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
30. 30.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
31. 31.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
32. 32.🔦 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
33. 33.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
34. 34.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
35. 35.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
36. 36.🔦 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 paper strip. Does the bulb glow? (a) Yes (b) No
37. 37.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
38. 38.Which of these means the circuit is open? (a) the switch is OFF (b) the switch is ON (c) all wires are joined (d) the loop is complete
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 plastic ruler. Does the bulb glow? (a) No (b) Yes
40. 40.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes

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