Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 769 · 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.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
2. 2.🔁 What must there be for a current to flow? (a) a broken path (b) one loose end (c) a plastic gap (d) a complete loop
3. 3.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) the bulb is unscrewed
4. 4.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
5. 5.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire is cut (c) the switch is ON (d) a cell is taken out
6. 6.🔁 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
7. 7.🔦 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
8. 8.🔦 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
9. 9.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
10. 10.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) a cell is taken out (d) the loop is complete
11. 11.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) none (c) both of them (d) only one
12. 12.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the glass (d) the filament
13. 13.🔦 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
14. 14.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
15. 15.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
16. 16.🔦 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) No (b) Yes
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 rubber eraser. Does the bulb glow? (a) Yes (b) No
18. 18.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
19. 19.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
20. 20.🔦 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
21. 21.Which of these means the circuit is closed? (a) a wire is cut (b) the bulb is unscrewed (c) a wire has come loose (d) all wires are joined
22. 22.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) the switch is OFF
23. 23.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
24. 24.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
25. 25.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
26. 26.🔦 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 graphite rod. Does the bulb glow? (a) No (b) Yes
27. 27.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
28. 28.Which of these means the circuit is open? (a) all wires are joined (b) a wire is cut (c) the switch is ON (d) the loop is complete
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) Yes (b) No
30. 30.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
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. One wire has come loose from the cell. Does the bulb glow? (a) Yes (b) No
33. 33.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
34. 34.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
35. 35.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
36. 36.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
37. 37.🔦 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 rubber eraser. Does the bulb glow? (a) No (b) Yes
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 glass marble. Does the bulb glow? (a) Yes (b) No
39. 39.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
40. 40.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open

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