Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 938 · 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.🔦 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
2. 2.🔦 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 wooden stick. Does the bulb glow? (a) No (b) Yes
3. 3.Which of these means the circuit is closed? (a) a wire has come loose (b) all wires are joined (c) a wire is cut (d) a cell is taken out
4. 4.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the base (c) the switch (d) the glass
5. 5.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
6. 6.Which of these means the circuit is open? (a) all wires are joined (b) the switch is OFF (c) the loop is complete (d) the switch is ON
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 ceramic cup. Does the bulb glow? (a) Yes (b) No
8. 8.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the switch is ON (c) all wires are joined (d) the loop is complete
9. 9.🔁 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
10. 10.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
11. 11.🔦 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
12. 12.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a closed circuit (d) a series circuit
13. 13.🔦 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 plastic straw. Does the bulb glow? (a) No (b) Yes
14. 14.🔦 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) No (b) Yes
15. 15.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a plastic gap (d) a complete loop
16. 16.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
17. 17.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
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 aluminium foil. Does the bulb glow? (a) No (b) Yes
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 rubber eraser. Does the bulb glow? (a) No (b) Yes
20. 20.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
21. 21.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
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 cotton thread. Does the bulb glow? (a) Yes (b) No
23. 23.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is ON (c) a cell is taken out (d) the switch is OFF
24. 24.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
25. 25.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
26. 26.🔦 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
27. 27.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
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 ceramic cup. Does the bulb glow? (a) Yes (b) No
29. 29.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
30. 30.🔁 Is the circuit closed or open if the bulb is unscrewed? (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 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. Does the bulb glow? (a) No (b) Yes
33. 33.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
34. 34.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
35. 35.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
36. 36.Which of these means the circuit is open? (a) a wire is cut (b) the loop is complete (c) the switch is ON (d) all wires are joined
37. 37.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
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 an iron nail. Does the bulb glow? (a) Yes (b) No
39. 39.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
40. 40.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open

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