Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 367 · 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 all wires are joined? (a) open (b) closed
2. 2.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
3. 3.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a cell is taken out
4. 4.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
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) none (d) it does not matter
6. 6.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
7. 7.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
8. 8.🔦 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 steel spoon. Does the bulb glow? (a) Yes (b) No
9. 9.🔦 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
10. 10.🔁 What must there be for a current to flow? (a) a complete loop (b) a plastic gap (c) one loose end (d) a broken path
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. A gap in one wire is bridged by a metal paper clip. Does the bulb glow? (a) Yes (b) No
12. 12.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
13. 13.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
14. 14.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a series circuit (c) a closed circuit (d) a full circuit
15. 15.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a wire has come loose
16. 16.Which of these means the circuit is closed? (a) a wire has come loose (b) the loop is complete (c) the switch is OFF (d) a cell is taken out
17. 17.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
18. 18.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
19. 19.🔦 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
20. 20.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a wire is cut (d) the loop is complete
21. 21.🔦 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
22. 22.🔦 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 plastic ruler. Does the bulb glow? (a) Yes (b) No
23. 23.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
24. 24.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
25. 25.🔦 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
27. 27.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is ON (c) a cell is taken out (d) the switch is OFF
28. 28.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
29. 29.🔦 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 rubber eraser. Does the bulb glow? (a) No (b) Yes
30. 30.🔦 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) No (b) Yes
31. 31.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
32. 32.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
33. 33.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the filament (d) the base
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) No (b) Yes
35. 35.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
36. 36.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
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 ceramic cup. Does the bulb glow? (a) No (b) Yes
38. 38.True or false: if a wire has come loose, 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 open and no current flows. (a) False (b) True
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 dry cork. Does the bulb glow? (a) No (b) Yes

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