Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 189 · 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 open? (a) the bulb is unscrewed (b) all wires are joined (c) the switch is ON (d) the loop is complete
2. 2.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is OFF (d) a cell is taken out
3. 3.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
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 steel spoon. Does the bulb glow? (a) Yes (b) No
5. 5.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
6. 6.🔦 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
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 safety pin. Does the bulb glow? (a) Yes (b) No
8. 8.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
9. 9.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
10. 10.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) none (c) both of them (d) only one
11. 11.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
12. 12.Which of these means the circuit is open? (a) the switch is ON (b) a wire is cut (c) the loop is complete (d) all wires are joined
13. 13.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a plastic gap (d) a broken path
14. 14.🔦 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) Yes (b) No
15. 15.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
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 rubber band. Does the bulb glow? (a) No (b) Yes
17. 17.🔁 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
18. 18.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
19. 19.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
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 woollen thread. Does the bulb glow? (a) Yes (b) No
21. 21.🔦 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) Yes (b) No
22. 22.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
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 an iron nail. Does the bulb glow? (a) No (b) Yes
24. 24.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
25. 25.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
26. 26.🔦 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
27. 27.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
28. 28.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
29. 29.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
30. 30.Which of these means the circuit is open? (a) a wire has come loose (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 OFF. All the wires are firmly joined. A gap in one wire is bridged by a steel coin. Does the bulb glow? (a) No (b) Yes
32. 32.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
33. 33.🔦 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
34. 34.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
35. 35.🔦 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 paper strip. Does the bulb glow? (a) Yes (b) No
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 ceramic cup. Does the bulb glow? (a) Yes (b) No
37. 37.Which of these means the circuit is open? (a) the switch is OFF (b) the switch is ON (c) the loop is complete (d) all wires are joined
38. 38.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
39. 39.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
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. Does the bulb glow? (a) Yes (b) No

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