Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 73 · 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.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full circuit
2. 2.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
3. 3.Which of these means the circuit is open? (a) the switch is OFF (b) the switch is ON (c) the loop is complete (d) all wires are joined
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 paper strip. Does the bulb glow? (a) Yes (b) No
5. 5.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
6. 6.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
7. 7.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
8. 8.🔁 What must there be for a current to flow? (a) a plastic gap (b) a complete loop (c) a broken path (d) one loose end
9. 9.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
10. 10.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is ON (c) a wire has come loose (d) a cell is taken out
11. 11.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
12. 12.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
13. 13.Which of these means the circuit is open? (a) all wires are joined (b) a wire is cut (c) the loop is complete (d) the switch is ON
14. 14.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
15. 15.🔦 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
16. 16.🔦 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) No (b) Yes
17. 17.🔁 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) only one (d) none
18. 18.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) all wires are joined (d) a wire has come loose
19. 19.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the switch (d) the base
20. 20.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
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 rubber band. Does the bulb glow? (a) No (b) Yes
22. 22.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the bulb is unscrewed
23. 23.🔦 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 coin. Does the bulb glow? (a) No (b) Yes
24. 24.🔦 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
25. 25.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
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 all wires are joined, the circuit is open and no current flows. (a) True (b) False
28. 28.Which of these means the circuit is closed? (a) the loop is complete (b) a wire is cut (c) the switch is OFF (d) a cell is taken out
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. Does the bulb glow? (a) No (b) Yes
30. 30.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
31. 31.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
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 a ceramic cup. Does the bulb glow? (a) Yes (b) No
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 copper wire. Does the bulb glow? (a) No (b) Yes
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 steel spoon. Does the bulb glow? (a) Yes (b) No
35. 35.🔦 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
36. 36.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
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 a plastic ruler. Does the bulb glow? (a) No (b) Yes
38. 38.🔦 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 steel spoon. Does the bulb glow? (a) No (b) Yes
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 woollen thread. Does the bulb glow? (a) No (b) Yes
40. 40.Which of these means the circuit is open? (a) a cell is taken out (b) all wires are joined (c) the switch is ON (d) the loop is complete

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