Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 740 · 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 the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
2. 2.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is OFF (d) the switch is ON
3. 3.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
4. 4.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
5. 5.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a series circuit (c) a full circuit (d) a closed circuit
6. 6.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
7. 7.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the glass (d) the base
8. 8.🔦 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
9. 9.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
10. 10.🔁 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
11. 11.🔦 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
12. 12.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) a wire has come loose (d) all wires are joined
13. 13.🔦 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
14. 14.🔦 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) Yes (b) No
15. 15.Which of these means the circuit is closed? (a) a wire has come loose (b) the loop is complete (c) a wire is cut (d) the switch is OFF
16. 16.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 bulb is unscrewed
17. 17.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
18. 18.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
19. 19.🔦 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 graphite rod. Does the bulb glow? (a) No (b) Yes
20. 20.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
21. 21.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
22. 22.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
23. 23.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a broken path (d) a plastic gap
24. 24.Which of these means the circuit is closed? (a) the switch is ON (b) a wire is cut (c) the switch is OFF (d) a wire has come loose
25. 25.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
26. 26.True or false: if the bulb is unscrewed, 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. One wire has come loose from the cell. A gap in one wire is bridged by a glass marble. Does the bulb glow? (a) No (b) Yes
28. 28.🔦 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 plastic straw. Does the bulb glow? (a) Yes (b) No
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 aluminium foil. Does the bulb glow? (a) No (b) Yes
30. 30.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
31. 31.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
32. 32.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
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 spoon. Does the bulb glow? (a) Yes (b) No
34. 34.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
35. 35.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
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 steel coin. Does the bulb glow? (a) Yes (b) No
37. 37.Which of these means the circuit is open? (a) all wires are joined (b) a wire has come loose (c) the loop is complete (d) the switch is ON
38. 38.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) the switch is ON (d) all wires are joined
39. 39.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
40. 40.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False

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