Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 76 · 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) closed (b) open
2. 2.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
3. 3.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
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 steel coin. Does the bulb glow? (a) Yes (b) No
5. 5.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
6. 6.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
7. 7.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
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 metal paper clip. Does the bulb glow? (a) No (b) Yes
9. 9.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
10. 10.🔦 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
11. 11.🔦 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) No (b) Yes
12. 12.Which of these means the circuit is open? (a) the switch is OFF (b) the loop is complete (c) the switch is ON (d) all wires are joined
13. 13.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
14. 14.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) a cell is taken out (d) the switch is ON
15. 15.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the switch (d) the glass
16. 16.🔁 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
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 copper wire. Does the bulb glow? (a) Yes (b) No
18. 18.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
19. 19.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
20. 20.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
21. 21.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
22. 22.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
23. 23.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
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.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
26. 26.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) a complete loop (d) one loose end
27. 27.🔁 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
28. 28.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
29. 29.🔦 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 plastic straw. Does the bulb glow? (a) Yes (b) No
30. 30.🔦 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
31. 31.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
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) Yes (b) No
33. 33.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
34. 34.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
35. 35.Which of these means the circuit is closed? (a) all wires are joined (b) the switch is OFF (c) a wire is cut (d) a cell is taken out
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 ceramic cup. Does the bulb glow? (a) No (b) Yes
37. 37.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) a cell is taken out (d) the loop is complete
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 woollen thread. Does the bulb glow? (a) No (b) Yes
39. 39.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
40. 40.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False

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