Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 671 · 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 complete loop (b) a plastic gap (c) a broken path (d) one loose end
2. 2.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
3. 3.🔦 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
4. 4.Which of these means the circuit is open? (a) the switch is ON (b) the switch is OFF (c) the loop is complete (d) all wires are joined
5. 5.Which of these means the circuit is open? (a) the loop is complete (b) a wire has come loose (c) all wires are joined (d) the switch is ON
6. 6.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) a wire is cut (d) the switch is ON
7. 7.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
8. 8.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a cell is taken out (d) the switch is ON
9. 9.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a full circuit (d) a series circuit
10. 10.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
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 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) both of them (d) none
13. 13.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) the bulb is unscrewed (d) the loop is complete
14. 14.Which of these means the circuit is closed? (a) all wires are joined (b) a wire has come loose (c) the bulb is unscrewed (d) the switch is OFF
15. 15.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
16. 16.🔦 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) No (b) Yes
17. 17.🔦 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
18. 18.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
19. 19.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
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 plastic straw. Does the bulb glow? (a) No (b) Yes
21. 21.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
22. 22.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
23. 23.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
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 graphite rod. Does the bulb glow? (a) Yes (b) No
25. 25.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
26. 26.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
27. 27.🔦 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 wooden stick. Does the bulb glow? (a) No (b) Yes
28. 28.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the base (c) the glass (d) the switch
29. 29.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
30. 30.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
31. 31.🔦 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
32. 32.🔦 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 plastic straw. Does the bulb glow? (a) No (b) Yes
33. 33.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
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 rubber band. Does the bulb glow? (a) No (b) Yes
35. 35.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
36. 36.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
37. 37.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the bulb is unscrewed
38. 38.🔦 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 aluminium foil. Does the bulb glow? (a) Yes (b) No
39. 39.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
40. 40.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes

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