Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 642 · 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. Does the bulb glow? (a) No (b) Yes
2. 2.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
3. 3.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) both of them (c) none (d) it does not matter
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 dry cork. Does the bulb glow? (a) Yes (b) No
5. 5.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
6. 6.🔦 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) No (b) Yes
7. 7.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
8. 8.🔦 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
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) open (b) closed
11. 11.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) an open circuit (d) a full circuit
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 paper strip. 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. 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
14. 14.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the switch is ON (c) the loop is complete (d) all wires are joined
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 ceramic cup. Does the bulb glow? (a) Yes (b) No
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 glass marble. Does the bulb glow? (a) No (b) Yes
17. 17.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
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 brass key. Does the bulb glow? (a) No (b) Yes
19. 19.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
20. 20.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
21. 21.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 cell is taken out
22. 22.Which of these means the circuit is closed? (a) a wire is cut (b) the bulb is unscrewed (c) a cell is taken out (d) the switch is ON
23. 23.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a complete loop (d) a plastic gap
24. 24.🔦 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 coin. Does the bulb glow? (a) Yes (b) No
25. 25.Which of these means the circuit is closed? (a) a wire is cut (b) a cell is taken out (c) all wires are joined (d) the switch is OFF
26. 26.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
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 brass key. Does the bulb glow? (a) No (b) Yes
28. 28.🔦 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 glass marble. Does the bulb glow? (a) Yes (b) No
29. 29.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
30. 30.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
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 cotton thread. Does the bulb glow? (a) No (b) Yes
32. 32.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
33. 33.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
34. 34.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
35. 35.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the base (c) the switch (d) the filament
36. 36.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
37. 37.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
38. 38.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
39. 39.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
40. 40.Which of these means the circuit is closed? (a) a wire is cut (b) the bulb is unscrewed (c) the loop is complete (d) the switch is OFF

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