Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 254 · 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 bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
2. 2.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
3. 3.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
4. 4.🔦 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
5. 5.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the glass (d) the switch
6. 6.🔦 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
7. 7.🔦 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
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 rubber eraser. Does the bulb glow? (a) No (b) Yes
9. 9.Which of these means the circuit is closed? (a) all wires are joined (b) a wire is cut (c) a cell is taken out (d) the switch is OFF
10. 10.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
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.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a plastic gap (d) a broken path
13. 13.🔦 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
14. 14.Which of these means the circuit is open? (a) the loop is complete (b) the bulb is unscrewed (c) all wires are joined (d) the switch is ON
15. 15.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) a wire has come loose
16. 16.🔦 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 safety pin. Does the bulb glow? (a) No (b) Yes
17. 17.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
18. 18.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) an open circuit (c) a full circuit (d) a closed circuit
19. 19.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) a wire has come loose (d) the switch is ON
20. 20.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
21. 21.🔦 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) Yes (b) No
22. 22.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
23. 23.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
24. 24.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
25. 25.Which of these means the circuit is open? (a) the loop is complete (b) a wire is cut (c) the switch is ON (d) all wires are joined
26. 26.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is OFF (c) the loop is complete (d) the bulb is unscrewed
27. 27.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
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 safety pin. Does the bulb glow? (a) No (b) Yes
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 a plastic ruler. Does the bulb glow? (a) No (b) Yes
30. 30.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a cell is taken out (d) the loop is complete
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 woollen thread. Does the bulb glow? (a) Yes (b) No
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 a ceramic cup. Does the bulb glow? (a) Yes (b) No
33. 33.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
34. 34.🔦 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
35. 35.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
36. 36.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
37. 37.🔦 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
38. 38.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
39. 39.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
40. 40.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open

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