Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 361 · 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) the switch is OFF (c) a wire has come loose (d) all wires are joined
2. 2.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
3. 3.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
4. 4.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is ON (c) a wire is cut (d) the switch is OFF
5. 5.Which of these means the circuit is open? (a) all wires are joined (b) the bulb is unscrewed (c) the loop is complete (d) the switch is ON
6. 6.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
7. 7.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a wire is cut (d) the switch is ON
8. 8.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
9. 9.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
10. 10.🔦 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) Yes (b) No
11. 11.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
12. 12.🔁 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
13. 13.🔦 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
14. 14.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a complete loop (d) a broken path
15. 15.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
16. 16.🔦 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
17. 17.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
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 cotton thread. Does the bulb glow? (a) No (b) Yes
19. 19.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
20. 20.🔦 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
21. 21.🔦 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) Yes (b) No
22. 22.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) the switch is OFF
23. 23.Which of these means the circuit is closed? (a) the loop is complete (b) a cell is taken out (c) the bulb is unscrewed (d) the switch is OFF
24. 24.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
25. 25.🔦 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
26. 26.🔦 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 band. Does the bulb glow? (a) No (b) Yes
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 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. Does the bulb glow? (a) No (b) Yes
29. 29.Which of these means the circuit is open? (a) the loop is complete (b) a cell is taken out (c) the switch is ON (d) all wires are joined
30. 30.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) an open circuit (c) a closed circuit (d) a full circuit
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 metal paper clip. Does the bulb glow? (a) No (b) Yes
32. 32.🔦 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) No (b) Yes
33. 33.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
34. 34.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
35. 35.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
36. 36.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
37. 37.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
38. 38.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
39. 39.🔦 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
40. 40.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True

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