Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 332 · 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.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) one loose end (d) a complete loop
2. 2.Which of these means the circuit is closed? (a) all wires are joined (b) a wire has come loose (c) a cell is taken out (d) a wire is cut
3. 3.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
4. 4.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
5. 5.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
6. 6.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
7. 7.🔦 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 cotton thread. Does the bulb glow? (a) Yes (b) No
8. 8.Which of these means the circuit is open? (a) a wire has come loose (b) the loop is complete (c) the switch is ON (d) all wires are joined
9. 9.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
10. 10.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
11. 11.🔦 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
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 a safety pin. Does the bulb glow? (a) Yes (b) No
13. 13.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
14. 14.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 switch is OFF
15. 15.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
16. 16.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
17. 17.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
18. 18.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
19. 19.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) none (d) both of them
20. 20.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a closed circuit (c) a series circuit (d) an open circuit
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 graphite rod. Does the bulb glow? (a) Yes (b) No
22. 22.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
23. 23.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
24. 24.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire is cut (c) the switch is ON (d) a wire has come loose
25. 25.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
26. 26.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) a wire is cut
27. 27.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
28. 28.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
29. 29.Which of these means the circuit is closed? (a) the loop is complete (b) a wire has come loose (c) the bulb is unscrewed (d) the switch is OFF
30. 30.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
31. 31.🔦 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 straw. Does the bulb glow? (a) No (b) Yes
32. 32.🔦 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
33. 33.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
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. A gap in one wire is bridged by a ceramic cup. Does the bulb glow? (a) Yes (b) No
35. 35.🔁 Is the circuit closed or open if a wire is cut? (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 woollen thread. Does the bulb glow? (a) Yes (b) No
37. 37.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
38. 38.🔦 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 eraser. Does the bulb glow? (a) Yes (b) No
39. 39.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the base (d) the switch
40. 40.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True

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