Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 817 · 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.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
2. 2.🔦 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
3. 3.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a cell is taken out (d) the switch is ON
4. 4.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
5. 5.🔁 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
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 glass marble. Does the bulb glow? (a) Yes (b) No
7. 7.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
8. 8.🔦 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) Yes (b) No
9. 9.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
10. 10.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) both of them (d) none
11. 11.🔦 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) No (b) Yes
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) Yes (b) No
13. 13.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the loop is complete (d) the switch is ON
14. 14.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) all wires are joined (d) a wire has come loose
15. 15.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
16. 16.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
17. 17.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is OFF (d) the switch is ON
18. 18.🔦 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
19. 19.🔦 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
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 metal paper clip. Does the bulb glow? (a) No (b) Yes
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 all wires are joined? (a) open (b) closed
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 aluminium foil. Does the bulb glow? (a) No (b) Yes
24. 24.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the bulb is unscrewed (d) the switch is ON
25. 25.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a wire is cut
26. 26.🔁 What must there be for a current to flow? (a) a plastic gap (b) one loose end (c) a broken path (d) a complete loop
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 brass key. Does the bulb glow? (a) No (b) Yes
28. 28.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
29. 29.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) the switch is ON (d) the bulb is unscrewed
30. 30.🔦 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
31. 31.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
32. 32.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
33. 33.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
34. 34.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) a cell is taken out (d) the loop is complete
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.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the base (d) the filament
37. 37.🔦 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) No (b) Yes
38. 38.🔦 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 rubber eraser. Does the bulb glow? (a) Yes (b) No
39. 39.🔦 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
40. 40.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed

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