Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 494 · 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 must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
2. 2.🔁 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
3. 3.Which of these means the circuit is closed? (a) a wire is cut (b) the bulb is unscrewed (c) the switch is OFF (d) the loop is complete
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.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
6. 6.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) all wires are joined (c) a wire is cut (d) the switch is OFF
7. 7.🔁 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) it does not matter (d) none
8. 8.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
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. Does the bulb glow? (a) No (b) Yes
10. 10.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
11. 11.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
12. 12.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
13. 13.🔦 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) No (b) Yes
14. 14.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
15. 15.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
16. 16.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
17. 17.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a cell is taken out (c) the switch is ON (d) a wire has come loose
18. 18.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
19. 19.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
20. 20.🔦 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
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 rubber band. Does the bulb glow? (a) No (b) Yes
22. 22.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
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) No (b) Yes
24. 24.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 switch is OFF
25. 25.🔦 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) No (b) Yes
26. 26.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
27. 27.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
28. 28.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the base (d) the glass
29. 29.True or false: if a cell is taken out, the circuit is closed and current flows. (a) False (b) True
30. 30.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
31. 31.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
32. 32.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
33. 33.Which of these means the circuit is open? (a) all wires are joined (b) a wire is cut (c) the switch is ON (d) the loop is complete
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 safety pin. Does the bulb glow? (a) No (b) Yes
35. 35.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
36. 36.🔦 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 spoon. 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. Does the bulb glow? (a) No (b) Yes
38. 38.🔦 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) Yes (b) No
39. 39.Which of these means the circuit is open? (a) a cell is taken out (b) all wires are joined (c) the loop is complete (d) the switch is ON
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 a brass key. Does the bulb glow? (a) No (b) Yes

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