Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 275 · 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 open? (a) all wires are joined (b) a wire is cut (c) the loop is complete (d) the switch is ON
2. 2.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
3. 3.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
4. 4.🔦 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 rubber eraser. Does the bulb glow? (a) No (b) Yes
5. 5.🔦 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) Yes (b) No
6. 6.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the glass (c) the switch (d) the filament
7. 7.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
8. 8.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a closed circuit (c) a series circuit (d) an open circuit
9. 9.🔦 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
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. A gap in one wire is bridged by a brass key. Does the bulb glow? (a) No (b) Yes
11. 11.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
12. 12.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
13. 13.🔁 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
14. 14.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
15. 15.Which of these means the circuit is closed? (a) the switch is OFF (b) the switch is ON (c) the bulb is unscrewed (d) a wire has come loose
16. 16.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
17. 17.🔦 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) No (b) Yes
18. 18.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
19. 19.🔦 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
20. 20.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the switch is ON (d) the loop is complete
21. 21.Which of these means the circuit is closed? (a) a cell is taken out (b) all wires are joined (c) the switch is OFF (d) a wire is cut
22. 22.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
23. 23.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
24. 24.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
25. 25.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is OFF (d) the switch is ON
26. 26.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a cell is taken out (d) all wires are joined
27. 27.🔦 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
28. 28.🔦 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) Yes (b) No
29. 29.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
30. 30.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
31. 31.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
32. 32.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the bulb is unscrewed (d) the loop is complete
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 steel coin. Does the bulb glow? (a) Yes (b) No
34. 34.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
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 plastic straw. Does the bulb glow? (a) No (b) Yes
36. 36.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
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 a brass key. 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. Does the bulb glow? (a) No (b) Yes
39. 39.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
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 plastic ruler. Does the bulb glow? (a) Yes (b) No

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