Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 764 · 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. One wire has come loose from the cell. A gap in one wire is bridged by a safety pin. Does the bulb glow? (a) Yes (b) No
2. 2.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
3. 3.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
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 steel spoon. Does the bulb glow? (a) Yes (b) No
5. 5.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is OFF (d) a cell is taken out
6. 6.🔁 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
7. 7.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
8. 8.🔦 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
9. 9.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
10. 10.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
11. 11.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the switch (d) the filament
12. 12.🔦 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
13. 13.🔦 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) No (b) Yes
14. 14.🔦 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
15. 15.🔦 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
16. 16.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
17. 17.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) both of them (c) none (d) only one
18. 18.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
19. 19.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
20. 20.🔦 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) Yes (b) No
21. 21.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
22. 22.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a full circuit (c) an open circuit (d) a closed circuit
23. 23.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
24. 24.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
25. 25.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
26. 26.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
27. 27.Which of these means the circuit is open? (a) a wire has come loose (b) the switch is ON (c) all wires are joined (d) the loop is complete
28. 28.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
29. 29.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
30. 30.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
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 a ceramic cup. Does the bulb glow? (a) No (b) Yes
32. 32.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
33. 33.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
34. 34.🔦 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
35. 35.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
36. 36.🔦 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 ceramic cup. Does the bulb glow? (a) No (b) Yes
37. 37.🔦 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 rubber band. Does the bulb glow? (a) Yes (b) No
38. 38.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
39. 39.🔦 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 plastic ruler. Does the bulb glow? (a) No (b) Yes
40. 40.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) the switch is ON (d) the bulb is unscrewed

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