Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 679 · 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.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) an open circuit (c) a series circuit (d) a closed circuit
2. 2.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
3. 3.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a plastic gap (d) a complete loop
4. 4.🔦 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
5. 5.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
6. 6.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
7. 7.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire is cut (c) a wire has come loose (d) the switch is ON
8. 8.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) only one (c) none (d) it does not matter
9. 9.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
10. 10.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) the loop is complete (d) a wire is cut
11. 11.Which of these means the circuit is open? (a) the loop is complete (b) the bulb is unscrewed (c) all wires are joined (d) the switch is ON
12. 12.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the base (d) the filament
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 steel coin. Does the bulb glow? (a) No (b) Yes
14. 14.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
15. 15.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
16. 16.Which of these means the circuit is closed? (a) the switch is OFF (b) a cell is taken out (c) a wire has come loose (d) all wires are joined
17. 17.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
18. 18.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
19. 19.Which of these means the circuit is open? (a) a wire has come loose (b) all wires are joined (c) the switch is ON (d) the loop is complete
20. 20.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
21. 21.🔦 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) No (b) Yes
22. 22.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
23. 23.🔦 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
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. A gap in one wire is bridged by a dry cork. Does the bulb glow? (a) No (b) Yes
25. 25.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
26. 26.🔦 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
27. 27.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
28. 28.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
29. 29.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
30. 30.🔦 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 straw. Does the bulb glow? (a) Yes (b) No
31. 31.🔦 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 glass marble. Does the bulb glow? (a) No (b) Yes
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. Does the bulb glow? (a) Yes (b) No
33. 33.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the switch is OFF
34. 34.🔦 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
35. 35.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
36. 36.🔦 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) No (b) Yes
37. 37.Which of these means the circuit is open? (a) the switch is ON (b) a wire is cut (c) all wires are joined (d) the loop is complete
38. 38.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
39. 39.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is ON (d) a cell is taken out
40. 40.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False

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