Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 693 · 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 switch is ON, the circuit is closed and current flows. (a) False (b) True
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
3. 3.🔁 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) only one (d) both of them
4. 4.🔁 What must there be for a current to flow? (a) a complete loop (b) a broken path (c) one loose end (d) a plastic gap
5. 5.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
6. 6.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
7. 7.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
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 steel coin. Does the bulb glow? (a) No (b) Yes
9. 9.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
10. 10.Which of these means the circuit is closed? (a) the loop is complete (b) a wire is cut (c) a wire has come loose (d) the switch is OFF
11. 11.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
12. 12.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
13. 13.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a full circuit (c) a closed circuit (d) a series circuit
14. 14.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
15. 15.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
16. 16.🔦 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 safety pin. Does the bulb glow? (a) No (b) Yes
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) No (b) Yes
18. 18.🔦 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 straw. Does the bulb glow? (a) No (b) Yes
19. 19.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) a cell is taken out
20. 20.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
21. 21.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
22. 22.🔦 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
23. 23.🔦 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 safety pin. Does the bulb glow? (a) No (b) Yes
24. 24.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
25. 25.🔦 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
26. 26.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
27. 27.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
28. 28.🔦 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) Yes (b) No
29. 29.🔦 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
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. 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. One wire has come loose from the cell. A gap in one wire is bridged by a woollen thread. Does the bulb glow? (a) No (b) Yes
33. 33.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
34. 34.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
35. 35.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
36. 36.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) a wire has come loose (d) all wires are joined
37. 37.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
38. 38.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
39. 39.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
40. 40.🔦 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) No (b) Yes

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