Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 630 · 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 a wire has come loose? (a) closed (b) open
2. 2.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
3. 3.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
4. 4.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
5. 5.🔁 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) none (d) only one
6. 6.🔦 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) No (b) Yes
7. 7.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) the bulb is unscrewed (d) all wires are joined
8. 8.🔦 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
9. 9.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
10. 10.🔁 What must there be for a current to flow? (a) a complete loop (b) one loose end (c) a plastic gap (d) a broken path
11. 11.🔦 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
12. 12.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
13. 13.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 cell is taken out
14. 14.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
15. 15.🔦 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 paper strip. Does the bulb glow? (a) Yes (b) No
16. 16.🔦 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) Yes (b) No
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 an iron nail. Does the bulb glow? (a) Yes (b) No
18. 18.Which of these means the circuit is closed? (a) the switch is ON (b) a cell is taken out (c) a wire is cut (d) a wire has come loose
19. 19.Which of these means the circuit is closed? (a) a wire has come loose (b) the bulb is unscrewed (c) the loop is complete (d) a cell is taken out
20. 20.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
21. 21.🔦 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
22. 22.Which of these means the circuit is open? (a) a wire is cut (b) the switch is ON (c) the loop is complete (d) all wires are joined
23. 23.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
24. 24.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
25. 25.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
26. 26.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
27. 27.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a full circuit (d) a series circuit
28. 28.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the filament (d) the base
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.🔁 Is the circuit closed or open if a cell is taken out? (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 plastic straw. Does the bulb glow? (a) No (b) Yes
32. 32.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
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 brass key. Does the bulb glow? (a) No (b) Yes
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 copper wire. Does the bulb glow? (a) Yes (b) No
35. 35.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the switch is OFF
36. 36.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
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 rubber eraser. Does the bulb glow? (a) Yes (b) No
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 steel spoon. Does the bulb glow? (a) No (b) Yes
39. 39.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
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 woollen thread. Does the bulb glow? (a) Yes (b) No

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