Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 419 · 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 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
2. 2.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 wire is cut
3. 3.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
4. 4.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
5. 5.🔦 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
6. 6.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
7. 7.🔁 What must there be for a current to flow? (a) a plastic gap (b) one loose end (c) a complete loop (d) a broken path
8. 8.🔦 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 plastic straw. Does the bulb glow? (a) No (b) Yes
9. 9.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
10. 10.🔁 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
11. 11.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) a wire is cut (d) the switch is ON
12. 12.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
13. 13.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
14. 14.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
15. 15.🔦 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
16. 16.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
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 steel coin. Does the bulb glow? (a) Yes (b) No
18. 18.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
19. 19.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
20. 20.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
21. 21.🔦 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 steel spoon. Does the bulb glow? (a) Yes (b) No
22. 22.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) an open circuit (d) a closed circuit
23. 23.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
24. 24.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
25. 25.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
26. 26.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
27. 27.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
28. 28.Which of these means the circuit is closed? (a) the loop is complete (b) the switch is OFF (c) a cell is taken out (d) the bulb is unscrewed
29. 29.Which of these means the circuit is open? (a) the loop is complete (b) a cell is taken out (c) all wires are joined (d) the switch is ON
30. 30.🔦 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 steel spoon. Does the bulb glow? (a) No (b) Yes
31. 31.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
32. 32.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
33. 33.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
34. 34.🔦 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
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) a wire has come loose (b) all wires are joined (c) the bulb is unscrewed (d) the switch is OFF
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 the switch is ON, the circuit is open and no current flows. (a) True (b) False
39. 39.🔦 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
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 wooden stick. Does the bulb glow? (a) No (b) Yes

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