Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 387 · 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) open (b) closed
2. 2.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a broken path (d) a complete loop
3. 3.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
4. 4.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
5. 5.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a cell is taken out (d) the switch is ON
6. 6.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
7. 7.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
8. 8.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
9. 9.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
10. 10.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the base (d) the switch
11. 11.🔦 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
12. 12.Which of these means the circuit is closed? (a) the loop is complete (b) a cell is taken out (c) the bulb is unscrewed (d) the switch is OFF
13. 13.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the bulb is unscrewed (d) the switch is ON
14. 14.🔦 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
15. 15.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
16. 16.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
17. 17.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
18. 18.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
19. 19.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
20. 20.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
21. 21.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
22. 22.Which of these means the circuit is closed? (a) all wires are joined (b) a cell is taken out (c) a wire has come loose (d) the bulb is unscrewed
23. 23.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
24. 24.🔦 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
25. 25.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire has come loose (c) the switch is ON (d) a wire is cut
26. 26.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) only one (c) both of them (d) it does not matter
27. 27.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
28. 28.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
29. 29.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a series circuit (d) a closed circuit
30. 30.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
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 copper wire. Does the bulb glow? (a) No (b) Yes
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. 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 a wire has come loose, the circuit is closed and current flows. (a) True (b) False
34. 34.🔦 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
35. 35.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
36. 36.🔦 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) Yes (b) No
37. 37.🔦 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
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 metal paper clip. Does the bulb glow? (a) No (b) Yes
39. 39.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
40. 40.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a wire has come loose

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