Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 461 · 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. A gap in one wire is bridged by a dry cork. Does the bulb glow? (a) No (b) Yes
2. 2.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
3. 3.🔁 What must there be for a current to flow? (a) a complete loop (b) one loose end (c) a plastic gap (d) a broken path
4. 4.🔦 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
5. 5.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
6. 6.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) the loop is complete (d) a cell is taken out
7. 7.🔦 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
8. 8.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) all wires are joined (d) a wire is cut
9. 9.🔦 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
10. 10.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
11. 11.🔦 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
12. 12.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
13. 13.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
14. 14.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
15. 15.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
16. 16.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
17. 17.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a series circuit (d) a closed circuit
18. 18.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) both of them (d) it does not matter
19. 19.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
20. 20.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
21. 21.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
22. 22.Which of these means the circuit is open? (a) all wires are joined (b) a wire is cut (c) the loop is complete (d) the switch is ON
23. 23.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the filament (d) the base
24. 24.🔦 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 paper strip. Does the bulb glow? (a) Yes (b) No
25. 25.Which of these means the circuit is closed? (a) the switch is ON (b) the switch is OFF (c) the bulb is unscrewed (d) a wire has come loose
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 aluminium foil. Does the bulb glow? (a) No (b) Yes
27. 27.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
28. 28.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
29. 29.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
30. 30.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
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 an iron nail. 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 cotton thread. Does the bulb glow? (a) No (b) Yes
33. 33.🔦 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) No (b) Yes
34. 34.🔦 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
35. 35.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
36. 36.🔦 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
37. 37.🔦 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 ruler. Does the bulb glow? (a) Yes (b) No
38. 38.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 has come loose
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. Does the bulb glow? (a) Yes (b) No
40. 40.🔦 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) Yes (b) No

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