Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 464 · 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.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
2. 2.Which of these means the circuit is closed? (a) all wires are joined (b) the switch is OFF (c) a wire has come loose (d) the bulb is unscrewed
3. 3.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) the bulb is unscrewed
4. 4.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
5. 5.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
6. 6.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
7. 7.🔦 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 eraser. Does the bulb glow? (a) Yes (b) No
8. 8.Which of these means the circuit is open? (a) a wire is cut (b) the loop is complete (c) the switch is ON (d) all wires are joined
9. 9.Which of these means the circuit is closed? (a) the loop is complete (b) the switch is OFF (c) a wire is cut (d) a cell is taken out
10. 10.🔦 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
11. 11.🔦 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
12. 12.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
13. 13.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
14. 14.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
15. 15.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
16. 16.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) the bulb is unscrewed (d) the switch is ON
17. 17.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) only one (d) it does not matter
18. 18.Which of these means the circuit is open? (a) the switch is ON (b) the switch is OFF (c) all wires are joined (d) the loop is complete
19. 19.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
20. 20.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
21. 21.🔦 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) Yes (b) No
22. 22.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
23. 23.🔦 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
24. 24.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
25. 25.🔦 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
26. 26.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
27. 27.🔦 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 ruler. Does the bulb glow? (a) No (b) Yes
28. 28.🔦 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
29. 29.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a closed circuit (d) a series circuit
30. 30.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
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 rubber band. Does the bulb glow? (a) No (b) Yes
32. 32.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
33. 33.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a wire has come loose (d) the loop is complete
34. 34.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
35. 35.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
36. 36.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
37. 37.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
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 a ceramic cup. Does the bulb glow? (a) Yes (b) No
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 ceramic cup. Does the bulb glow? (a) No (b) Yes
40. 40.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open

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