Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 583 · 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) the bulb is unscrewed (b) the switch is OFF (c) all wires are joined (d) a wire is cut
2. 2.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
3. 3.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
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 paper strip. Does the bulb glow? (a) Yes (b) No
5. 5.🔦 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
6. 6.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
7. 7.🔦 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) Yes (b) No
8. 8.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a wire is cut (d) the loop is complete
9. 9.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
10. 10.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
11. 11.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the base (d) the glass
12. 12.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a full circuit (d) a series circuit
13. 13.Which of these means the circuit is closed? (a) a wire is cut (b) the bulb is unscrewed (c) the switch is OFF (d) the switch is ON
14. 14.🔦 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 graphite rod. Does the bulb glow? (a) No (b) Yes
15. 15.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
16. 16.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
17. 17.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
18. 18.🔁 Is the circuit closed or open if the bulb is unscrewed? (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.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) a wire has come loose
21. 21.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
22. 22.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) none (c) only one (d) it does not matter
23. 23.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
24. 24.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) the loop is complete (d) the switch is OFF
25. 25.🔁 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
26. 26.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
27. 27.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
28. 28.🔦 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
29. 29.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
30. 30.🔁 Is the circuit closed or open if a cell is taken out? (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 plastic ruler. Does the bulb glow? (a) No (b) Yes
32. 32.True or false: if the bulb is unscrewed, 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 rubber eraser. Does the bulb glow? (a) No (b) Yes
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 safety pin. Does the bulb glow? (a) No (b) Yes
35. 35.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
36. 36.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
37. 37.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
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. Does the bulb glow? (a) Yes (b) No
39. 39.Which of these means the circuit is open? (a) the loop is complete (b) the bulb is unscrewed (c) the switch is ON (d) all wires are joined
40. 40.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True

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