Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 650 · 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) the loop is complete (b) a wire is cut (c) the switch is ON (d) all wires are joined
2. 2.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
3. 3.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) both of them (d) only one
4. 4.🔁 What must there be for a current to flow? (a) a plastic gap (b) a broken path (c) one loose end (d) a complete loop
5. 5.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full 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.Which of these means the circuit is closed? (a) a wire has come loose (b) all wires are joined (c) the switch is OFF (d) the bulb is unscrewed
8. 8.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is ON (c) a wire has come loose (d) the switch is OFF
9. 9.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
10. 10.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
11. 11.Which of these means the circuit is closed? (a) a wire is cut (b) a wire has come loose (c) the bulb is unscrewed (d) the loop is complete
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. A gap in one wire is bridged by a wooden stick. Does the bulb glow? (a) Yes (b) No
13. 13.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
14. 14.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
15. 15.🔦 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
16. 16.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the glass (c) the switch (d) the filament
17. 17.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
18. 18.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
19. 19.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
20. 20.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
21. 21.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
22. 22.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a cell is taken out (d) all wires are joined
23. 23.🔦 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
24. 24.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
25. 25.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
26. 26.🔦 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
27. 27.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
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) No (b) Yes
29. 29.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
30. 30.🔦 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) No (b) Yes
31. 31.Which of these means the circuit is open? (a) all wires are joined (b) a wire has come loose (c) the switch is ON (d) the loop is complete
32. 32.🔦 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
33. 33.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
34. 34.🔦 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
35. 35.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
36. 36.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
37. 37.🔦 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
38. 38.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
39. 39.🔦 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 plastic straw. Does the bulb glow? (a) Yes (b) No
40. 40.Which of these means the circuit is open? (a) the bulb is unscrewed (b) the switch is ON (c) all wires are joined (d) the loop is complete

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