Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 685 · 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.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) an open circuit (d) a full circuit
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 a steel coin. Does the bulb glow? (a) No (b) Yes
3. 3.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
4. 4.🔦 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 ceramic cup. 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 switch (d) the glass
6. 6.🔁 What must there be for a current to flow? (a) a plastic gap (b) a complete loop (c) a broken path (d) one loose end
7. 7.🔦 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
8. 8.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
9. 9.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
10. 10.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
11. 11.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
12. 12.Which of these means the circuit is closed? (a) all wires are joined (b) a cell is taken out (c) the switch is OFF (d) a wire is cut
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 brass key. 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. One wire has come loose from the cell. A gap in one wire is bridged by a graphite rod. Does the bulb glow? (a) No (b) Yes
15. 15.Which of these means the circuit is closed? (a) the loop is complete (b) a cell is taken out (c) a wire is cut (d) a wire has come loose
16. 16.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
17. 17.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
18. 18.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the bulb is unscrewed (d) the loop is complete
19. 19.🔦 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) No (b) Yes
20. 20.Which of these means the circuit is open? (a) a cell is taken out (b) the switch is ON (c) all wires are joined (d) the loop is complete
21. 21.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
22. 22.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
23. 23.Which of these means the circuit is open? (a) the switch is OFF (b) the switch is ON (c) the loop is complete (d) all wires are joined
24. 24.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
25. 25.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
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 woollen thread. Does the bulb glow? (a) No (b) Yes
27. 27.🔦 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
28. 28.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
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 graphite rod. Does the bulb glow? (a) Yes (b) No
30. 30.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
31. 31.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
32. 32.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
33. 33.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
34. 34.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
35. 35.🔦 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) Yes (b) No
36. 36.🔦 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) No (b) Yes
37. 37.Which of these means the circuit is open? (a) a wire is cut (b) the loop is complete (c) all wires are joined (d) the switch is ON
38. 38.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
39. 39.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
40. 40.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No

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