Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 879 · 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 safety pin. Does the bulb glow? (a) Yes (b) No
2. 2.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
3. 3.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) a full circuit (d) an open circuit
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 aluminium foil. Does the bulb glow? (a) Yes (b) No
5. 5.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a broken path (d) a plastic gap
6. 6.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 is cut
7. 7.🔦 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
8. 8.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
9. 9.🔦 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
10. 10.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
11. 11.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
12. 12.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
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) Yes (b) No
14. 14.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
15. 15.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
16. 16.🔦 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 woollen thread. Does the bulb glow? (a) Yes (b) No
17. 17.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
18. 18.Which of these means the circuit is closed? (a) the switch is ON (b) the switch is OFF (c) a wire is cut (d) the bulb is unscrewed
19. 19.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) only one (c) none (d) both of them
20. 20.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
21. 21.🔦 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
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 an iron nail. Does the bulb glow? (a) No (b) Yes
23. 23.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) a wire has come loose
24. 24.Which of these means the circuit is open? (a) the switch is ON (b) a cell is taken out (c) the loop is complete (d) all wires are joined
25. 25.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
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 a rubber band. Does the bulb glow? (a) Yes (b) No
27. 27.🔦 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
28. 28.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the bulb is unscrewed (d) the switch is ON
29. 29.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
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 steel spoon. Does the bulb glow? (a) No (b) Yes
31. 31.🔦 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
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 dry cork. Does the bulb glow? (a) No (b) Yes
33. 33.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
34. 34.🔦 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
35. 35.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
36. 36.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
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 plastic straw. Does the bulb glow? (a) Yes (b) No
38. 38.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
39. 39.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the base (c) the filament (d) the glass
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) Yes (b) No

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