Electronics Worksheet: Simple Circuit – Open and Closed

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

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