Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 634 · 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.🔦 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
2. 2.🔦 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
3. 3.🔦 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) Yes (b) No
4. 4.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) a cell is taken out
5. 5.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) both of them (c) it does not matter (d) none
6. 6.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) a series circuit (d) an open circuit
7. 7.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
8. 8.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
9. 9.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
10. 10.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) a cell is taken out (d) all wires are joined
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.🔦 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
13. 13.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) one loose end (d) a complete loop
14. 14.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
15. 15.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
16. 16.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) the loop is complete (d) the switch is OFF
17. 17.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
18. 18.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
19. 19.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
20. 20.🔦 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
21. 21.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
22. 22.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
23. 23.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
24. 24.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
25. 25.Which of these means the circuit is open? (a) the switch is ON (b) the bulb is unscrewed (c) the loop is complete (d) all wires are joined
26. 26.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
27. 27.🔦 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) Yes (b) No
28. 28.🔦 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
29. 29.🔦 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
30. 30.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
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 rubber eraser. Does the bulb glow? (a) No (b) Yes
32. 32.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
33. 33.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
34. 34.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the base (d) the glass
35. 35.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
36. 36.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
37. 37.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
38. 38.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
39. 39.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
40. 40.🔦 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

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