Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 707 · 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 switch is ON? (a) open (b) closed
2. 2.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
3. 3.🔁 What must there be for a current to flow? (a) a plastic gap (b) one loose end (c) a complete loop (d) a broken path
4. 4.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) a wire is cut
5. 5.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
6. 6.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) a wire is cut (d) the switch is ON
7. 7.🔦 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 ceramic cup. Does the bulb glow? (a) Yes (b) No
8. 8.🔦 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 cotton thread. Does the bulb glow? (a) Yes (b) No
9. 9.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
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 a wooden stick. Does the bulb glow? (a) Yes (b) No
11. 11.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
12. 12.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
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 graphite rod. Does the bulb glow? (a) No (b) Yes
14. 14.🔦 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
15. 15.🔁 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
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 copper wire. Does the bulb glow? (a) No (b) Yes
17. 17.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
18. 18.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
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 glass marble. Does the bulb glow? (a) Yes (b) No
20. 20.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) an open circuit (d) a full circuit
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. A gap in one wire is bridged by a paper strip. Does the bulb glow? (a) Yes (b) No
22. 22.Which of these means the circuit is open? (a) all wires are joined (b) a cell is taken out (c) the loop is complete (d) the switch is ON
23. 23.Which of these means the circuit is closed? (a) a wire is cut (b) the loop is complete (c) a wire has come loose (d) a cell is taken out
24. 24.🔦 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
25. 25.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
26. 26.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
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 ceramic cup. Does the bulb glow? (a) No (b) Yes
28. 28.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
29. 29.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
30. 30.🔦 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) Yes (b) No
31. 31.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
32. 32.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
33. 33.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
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 steel spoon. Does the bulb glow? (a) Yes (b) No
35. 35.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the bulb is unscrewed (d) the switch is ON
36. 36.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
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 safety pin. Does the bulb glow? (a) Yes (b) No
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 paper strip. Does the bulb glow? (a) Yes (b) No
39. 39.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the glass (d) the base
40. 40.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True

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