Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 209 · 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.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
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 safety pin. Does the bulb glow? (a) Yes (b) No
3. 3.🔦 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
4. 4.🔦 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
5. 5.🔦 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
6. 6.🔦 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
7. 7.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) a closed circuit (d) an open circuit
8. 8.🔦 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
9. 9.🔁 What must there be for a current to flow? (a) a complete loop (b) a plastic gap (c) one loose end (d) a broken path
10. 10.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
11. 11.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
12. 12.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) the switch is ON (d) a cell is taken out
13. 13.🔦 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
14. 14.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
15. 15.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
16. 16.🔦 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
17. 17.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
18. 18.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a wire has come loose
19. 19.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the base (c) the filament (d) the glass
20. 20.🔦 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
21. 21.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
22. 22.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
23. 23.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a cell is taken out (d) all wires are joined
24. 24.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
25. 25.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
26. 26.Which of these means the circuit is closed? (a) a cell is taken out (b) all wires are joined (c) the switch is OFF (d) a wire has come loose
27. 27.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
28. 28.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
29. 29.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
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 copper wire. Does the bulb glow? (a) Yes (b) No
31. 31.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
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 glass marble. 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. 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
34. 34.Which of these means the circuit is open? (a) the loop is complete (b) the switch is OFF (c) all wires are joined (d) the switch is ON
35. 35.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
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.🔦 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) No (b) Yes
38. 38.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) both of them (d) none
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 plastic ruler. Does the bulb glow? (a) No (b) Yes
40. 40.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) the bulb is unscrewed

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