Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 664 · 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 a wire has come loose? (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 brass key. Does the bulb glow? (a) No (b) Yes
3. 3.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is ON (c) a cell is taken out (d) a wire has come loose
4. 4.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
5. 5.🔦 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
6. 6.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) a wire is cut (d) the loop is complete
7. 7.🔦 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
8. 8.🔦 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
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. 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
11. 11.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
12. 12.🔦 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
13. 13.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the base (c) the filament (d) the glass
14. 14.🔦 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
15. 15.🔦 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
16. 16.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
17. 17.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
18. 18.🔁 What must there be for a current to flow? (a) a complete loop (b) one loose end (c) a plastic gap (d) a broken path
19. 19.Which of these means the circuit is open? (a) the loop is complete (b) a cell is taken out (c) all wires are joined (d) the switch is ON
20. 20.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) both of them (c) only one (d) it does not matter
21. 21.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) a full circuit (d) an open circuit
22. 22.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
23. 23.Which of these means the circuit is open? (a) the switch is ON (b) a wire has come loose (c) the loop is complete (d) all wires are joined
24. 24.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the bulb is unscrewed (d) the loop is complete
25. 25.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
26. 26.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
27. 27.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
28. 28.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
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. Does the bulb glow? (a) No (b) Yes
30. 30.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
31. 31.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
32. 32.🔦 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 copper wire. Does the bulb glow? (a) No (b) Yes
33. 33.🔦 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
34. 34.🔦 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) 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. A gap in one wire is bridged by aluminium foil. Does the bulb glow? (a) Yes (b) No
36. 36.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
37. 37.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) the switch is OFF
38. 38.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
39. 39.🔦 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
40. 40.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a wire is cut (d) the loop is complete

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