Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 337 · 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 switch is ON (b) all wires are joined (c) the loop is complete (d) a wire has come loose
2. 2.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
3. 3.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) the switch is OFF (d) all wires are joined
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 an iron nail. Does the bulb glow? (a) No (b) Yes
5. 5.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
6. 6.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
7. 7.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
8. 8.Which of these means the circuit is open? (a) a cell is taken out (b) all wires are joined (c) the switch is ON (d) the loop is complete
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. A gap in one wire is bridged by a graphite rod. Does the bulb glow? (a) Yes (b) No
10. 10.🔦 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
11. 11.Which of these means the circuit is closed? (a) the switch is OFF (b) a wire has come loose (c) a wire is cut (d) the loop is complete
12. 12.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
13. 13.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
14. 14.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
15. 15.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
16. 16.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
17. 17.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
18. 18.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
19. 19.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a broken path (d) a plastic gap
20. 20.🔦 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 wooden stick. Does the bulb glow? (a) Yes (b) No
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 wooden stick. Does the bulb glow? (a) Yes (b) No
22. 22.🔦 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
23. 23.🔁 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
24. 24.🔦 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 steel coin. Does the bulb glow? (a) Yes (b) No
25. 25.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
26. 26.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
27. 27.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) only one (c) it does not matter (d) both of them
28. 28.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
29. 29.🔦 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 dry cork. Does the bulb glow? (a) No (b) Yes
30. 30.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
31. 31.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
32. 32.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
33. 33.Which of these means the circuit is closed? (a) the switch is OFF (b) the switch is ON (c) the bulb is unscrewed (d) a wire is cut
34. 34.🔦 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
35. 35.🔦 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
36. 36.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
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 ceramic cup. Does the bulb glow? (a) No (b) Yes
38. 38.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
39. 39.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
40. 40.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes

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