Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 944 · 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.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) a wire is cut
2. 2.🔦 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
3. 3.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the filament (d) the glass
4. 4.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
5. 5.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
6. 6.🔦 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
7. 7.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
8. 8.Which of these means the circuit is closed? (a) the switch is OFF (b) the loop is complete (c) the bulb is unscrewed (d) a wire has come loose
9. 9.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) it does not matter (c) none (d) only one
10. 10.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
11. 11.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) a wire is cut
12. 12.🔦 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) No (b) Yes
13. 13.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) the switch is ON (d) a wire is cut
14. 14.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
15. 15.Which of these means the circuit is open? (a) all wires are joined (b) the bulb is unscrewed (c) the loop is complete (d) the switch is ON
16. 16.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
17. 17.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
18. 18.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a cell is taken out (d) the switch is ON
19. 19.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a broken path (d) a complete loop
20. 20.🔦 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 rubber eraser. Does the bulb glow? (a) Yes (b) No
21. 21.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
22. 22.🔦 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
23. 23.Which of these means the circuit is open? (a) the switch is ON (b) a wire has come loose (c) all wires are joined (d) the loop is complete
24. 24.Which of these means the circuit is open? (a) all wires are joined (b) the switch is OFF (c) the switch is ON (d) the loop is complete
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 plastic straw. Does the bulb glow? (a) Yes (b) No
26. 26.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
27. 27.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
28. 28.🔦 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
29. 29.True or false: if the switch is ON, 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 paper strip. Does the bulb glow? (a) Yes (b) No
31. 31.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
32. 32.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
33. 33.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
34. 34.🔦 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 plastic ruler. Does the bulb glow? (a) Yes (b) No
35. 35.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
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) Yes (b) No
37. 37.🔁 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
38. 38.True or false: if a wire is cut, the circuit is closed and 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. Does the bulb glow? (a) No (b) Yes
40. 40.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True

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