Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 225 · 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.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a series circuit (c) a closed circuit (d) an open circuit
2. 2.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a cell is taken out (d) the switch is ON
3. 3.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
4. 4.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
5. 5.Which of these means the circuit is closed? (a) all wires are joined (b) a wire is cut (c) a wire has come loose (d) the switch is OFF
6. 6.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
7. 7.🔁 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) it does not matter (d) none
8. 8.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
9. 9.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the switch (d) the glass
10. 10.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
11. 11.🔦 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
12. 12.🔁 What must there be for a current to flow? (a) a complete loop (b) a broken path (c) a plastic gap (d) one loose end
13. 13.Which of these means the circuit is open? (a) a wire is cut (b) the loop is complete (c) all wires are joined (d) the switch is ON
14. 14.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
15. 15.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
16. 16.Which of these means the circuit is closed? (a) the loop is complete (b) a cell is taken out (c) a wire is cut (d) the switch is OFF
17. 17.🔦 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
18. 18.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
19. 19.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
20. 20.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
21. 21.Which of these means the circuit is closed? (a) the switch is ON (b) the bulb is unscrewed (c) a wire is cut (d) a wire has come loose
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 wooden stick. 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. One wire has come loose from the cell. A gap in one wire is bridged by an iron nail. Does the bulb glow? (a) No (b) Yes
24. 24.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
25. 25.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
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 rubber band. Does the bulb glow? (a) No (b) Yes
27. 27.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
28. 28.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
29. 29.🔦 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 ruler. Does the bulb glow? (a) No (b) Yes
30. 30.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
31. 31.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
32. 32.🔦 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) No (b) Yes
33. 33.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
34. 34.🔦 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) Yes (b) No
35. 35.🔦 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
36. 36.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
37. 37.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
38. 38.🔦 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
39. 39.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
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 copper wire. Does the bulb glow? (a) No (b) Yes

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