Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 758 · 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 closed? (a) a cell is taken out (b) all wires are joined (c) a wire has come loose (d) a wire is cut
2. 2.🔦 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
3. 3.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
4. 4.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) a closed circuit (d) an open circuit
5. 5.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the base (d) the glass
6. 6.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
7. 7.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
8. 8.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is ON (d) all wires are joined
9. 9.🔦 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
10. 10.Which of these means the circuit is open? (a) a wire has come loose (b) the loop is complete (c) the switch is ON (d) all wires are joined
11. 11.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
12. 12.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
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.🔁 What must there be for a current to flow? (a) a complete loop (b) a broken path (c) a plastic gap (d) one loose end
15. 15.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
16. 16.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
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 graphite rod. Does the bulb glow? (a) Yes (b) No
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 plastic straw. Does the bulb glow? (a) Yes (b) No
19. 19.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) a cell is taken out
20. 20.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
21. 21.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
22. 22.🔦 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
23. 23.🔦 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) Yes (b) No
24. 24.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
25. 25.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
26. 26.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
27. 27.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
28. 28.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
29. 29.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) the switch is ON (d) the switch is OFF
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 woollen thread. 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. One wire has come loose from the cell. A gap in one wire is bridged by aluminium foil. Does the bulb glow? (a) Yes (b) No
32. 32.🔦 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 spoon. Does the bulb glow? (a) No (b) Yes
33. 33.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
34. 34.🔦 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 rubber eraser. Does the bulb glow? (a) No (b) Yes
35. 35.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
36. 36.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
37. 37.🔦 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
38. 38.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
39. 39.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
40. 40.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) both of them (d) only one

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