Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 349 · 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.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the loop is complete (c) a wire is cut (d) a cell is taken out
2. 2.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) a full circuit (d) an open circuit
3. 3.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a cell is taken out (d) the loop is complete
4. 4.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire is cut (c) all wires are joined (d) a wire has come loose
5. 5.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
6. 6.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is ON (c) a wire is cut (d) a wire has come loose
7. 7.🔦 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
8. 8.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
9. 9.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
10. 10.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
11. 11.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
12. 12.🔦 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) No (b) Yes
13. 13.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
14. 14.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
15. 15.🔁 Is the circuit closed or open if the loop is complete? (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. Does the bulb glow? (a) No (b) Yes
17. 17.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
18. 18.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a plastic gap (d) a complete loop
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 paper strip. Does the bulb glow? (a) Yes (b) No
20. 20.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the filament (d) the base
21. 21.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
22. 22.🔁 Is the circuit closed or open if a cell is taken out? (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 rubber band. Does the bulb glow? (a) Yes (b) No
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 ceramic cup. Does the bulb glow? (a) No (b) Yes
25. 25.Which of these means the circuit is open? (a) the switch is OFF (b) all wires are joined (c) the loop is complete (d) the switch is ON
26. 26.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
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 straw. Does the bulb glow? (a) No (b) Yes
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.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
30. 30.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
31. 31.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) the bulb is unscrewed
32. 32.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
33. 33.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
34. 34.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
35. 35.🔦 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) Yes (b) No
36. 36.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
37. 37.🔁 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
38. 38.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
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 glass marble. Does the bulb glow? (a) No (b) Yes
40. 40.🔦 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 steel spoon. Does the bulb glow? (a) Yes (b) No

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