Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 636 · 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 open? (a) a wire has come loose (b) the switch is ON (c) all wires are joined (d) the loop is complete
2. 2.Which of these means the circuit is closed? (a) the switch is OFF (b) the loop is complete (c) a wire has come loose (d) a wire is cut
3. 3.Which of these means the circuit is closed? (a) all wires are joined (b) a cell is taken out (c) the bulb is unscrewed (d) the switch is OFF
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 safety pin. Does the bulb glow? (a) Yes (b) No
5. 5.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
6. 6.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
7. 7.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
8. 8.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the glass (c) the switch (d) the base
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) Yes (b) No
10. 10.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
11. 11.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
12. 12.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
13. 13.🔁 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
14. 14.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
15. 15.🔦 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
16. 16.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
17. 17.🔦 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
18. 18.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
19. 19.🔁 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
20. 20.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) a complete loop (d) one loose end
21. 21.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
22. 22.🔦 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) Yes (b) No
23. 23.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
24. 24.🔦 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) Yes (b) No
25. 25.Which of these means the circuit is open? (a) the switch is ON (b) the switch is OFF (c) the loop is complete (d) all wires are joined
26. 26.🔦 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) Yes (b) No
27. 27.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
28. 28.🔦 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) Yes (b) No
29. 29.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
30. 30.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
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 brass key. Does the bulb glow? (a) No (b) Yes
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 cotton thread. Does the bulb glow? (a) Yes (b) No
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) Yes (b) No
34. 34.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
35. 35.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
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 a wooden stick. Does the bulb glow? (a) No (b) Yes
37. 37.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
38. 38.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
39. 39.Which of these means the circuit is closed? (a) the switch is ON (b) a cell is taken out (c) the bulb is unscrewed (d) the switch is OFF
40. 40.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a series circuit (d) a full circuit

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