Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 542 · 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) all wires are joined (c) the switch is ON (d) the bulb is unscrewed
2. 2.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
3. 3.Which of these means the circuit is closed? (a) the switch is ON (b) the bulb is unscrewed (c) a cell is taken out (d) a wire has come loose
4. 4.🔦 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) Yes (b) No
5. 5.🔁 What must there be for a current to flow? (a) a broken path (b) a plastic gap (c) one loose end (d) a complete loop
6. 6.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a closed circuit (c) a series circuit (d) an open circuit
7. 7.Which of these means the circuit is closed? (a) the switch is OFF (b) all wires are joined (c) a wire is cut (d) a wire has come loose
8. 8.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
9. 9.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
10. 10.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
11. 11.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
12. 12.🔦 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
13. 13.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a cell is taken out (d) the loop is complete
14. 14.🔦 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
15. 15.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) a cell is taken out (d) the loop is complete
16. 16.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
17. 17.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
18. 18.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
19. 19.🔦 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
20. 20.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
21. 21.🔦 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
22. 22.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the switch (d) the base
23. 23.🔦 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) No (b) Yes
24. 24.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
25. 25.🔦 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
26. 26.🔦 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
27. 27.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) none (c) only one (d) both of them
28. 28.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
29. 29.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
30. 30.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
31. 31.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
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. A gap in one wire is bridged by a dry cork. Does the bulb glow? (a) No (b) Yes
33. 33.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire is cut (d) all wires are joined
34. 34.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
35. 35.🔦 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
36. 36.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
37. 37.🔦 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
38. 38.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
39. 39.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
40. 40.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False

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