Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 260 · 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. Does the bulb glow? (a) No (b) Yes
2. 2.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the base (c) the filament (d) the glass
3. 3.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
4. 4.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
5. 5.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
6. 6.🔦 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
7. 7.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
8. 8.Which of these means the circuit is open? (a) the switch is OFF (b) all wires are joined (c) the switch is ON (d) the loop is complete
9. 9.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
10. 10.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
11. 11.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
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) Yes (b) No
13. 13.🔦 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
14. 14.🔁 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) it does not matter (d) none
15. 15.Which of these means the circuit is open? (a) the switch is ON (b) a wire has come loose (c) the loop is complete (d) all wires are joined
16. 16.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) all wires are joined (c) a cell is taken out (d) a wire is cut
17. 17.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
18. 18.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
19. 19.🔦 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
20. 20.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
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 plastic straw. Does the bulb glow? (a) Yes (b) No
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 brass key. Does the bulb glow? (a) No (b) Yes
23. 23.🔁 What must there be for a current to flow? (a) a complete loop (b) a plastic gap (c) a broken path (d) one loose end
24. 24.🔦 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
25. 25.Which of these means the circuit is open? (a) a cell is taken out (b) the loop is complete (c) all wires are joined (d) the switch is ON
26. 26.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
27. 27.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
28. 28.🔦 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
29. 29.True or false: if the loop is complete, the circuit is open and no 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
31. 31.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
32. 32.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
33. 33.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
34. 34.🔁 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
35. 35.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
36. 36.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
37. 37.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
38. 38.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
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 steel spoon. Does the bulb glow? (a) No (b) Yes
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 dry cork. Does the bulb glow? (a) Yes (b) No

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