Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 166 · 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.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
2. 2.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
3. 3.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
4. 4.🔁 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
5. 5.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
6. 6.Which of these means the circuit is closed? (a) a wire is cut (b) a cell is taken out (c) a wire has come loose (d) all wires are joined
7. 7.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
8. 8.🔦 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) Yes (b) No
9. 9.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the switch (d) the glass
10. 10.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) the bulb is unscrewed
11. 11.🔦 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
12. 12.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
13. 13.🔦 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 steel coin. Does the bulb glow? (a) No (b) Yes
14. 14.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
15. 15.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a cell is taken out
16. 16.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a series circuit (c) an open circuit (d) a full circuit
17. 17.🔁 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
18. 18.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a wire is cut (d) the loop is complete
19. 19.🔦 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
20. 20.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
21. 21.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
22. 22.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
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 rubber eraser. Does the bulb glow? (a) Yes (b) No
24. 24.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
25. 25.🔦 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 rubber band. Does the bulb glow? (a) Yes (b) No
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. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) Yes (b) No
27. 27.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
28. 28.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
29. 29.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
30. 30.🔦 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 plastic straw. Does the bulb glow? (a) Yes (b) No
31. 31.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
32. 32.🔦 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 an iron nail. Does the bulb glow? (a) No (b) Yes
33. 33.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) a wire has come loose
34. 34.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
35. 35.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
36. 36.Which of these means the circuit is closed? (a) a wire has come loose (b) a wire is cut (c) a cell is taken out (d) the loop is complete
37. 37.🔦 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
38. 38.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
39. 39.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
40. 40.🔦 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 rubber eraser. Does the bulb glow? (a) No (b) Yes

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