Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 593 · 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) True (b) False
2. 2.🔦 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
3. 3.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
4. 4.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
5. 5.True or false: if a wire has come loose, the circuit is closed and current flows. (a) False (b) True
6. 6.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
7. 7.🔦 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
8. 8.🔦 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
9. 9.🔦 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
10. 10.🔦 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 woollen thread. Does the bulb glow? (a) No (b) Yes
11. 11.🔦 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) Yes (b) No
12. 12.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
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 ceramic cup. Does the bulb glow? (a) Yes (b) No
14. 14.🔦 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) No (b) Yes
15. 15.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
16. 16.🔦 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) No (b) Yes
17. 17.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) all wires are joined (d) a cell is taken out
18. 18.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
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) Yes (b) No
20. 20.Which of these means the circuit is closed? (a) the switch is ON (b) a cell is taken out (c) the switch is OFF (d) a wire is cut
21. 21.Which of these means the circuit is closed? (a) the loop is complete (b) the bulb is unscrewed (c) a cell is taken out (d) a wire is cut
22. 22.🔦 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) No (b) Yes
23. 23.🔦 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 rubber eraser. Does the bulb glow? (a) Yes (b) No
24. 24.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) a wire is cut (d) the loop is complete
25. 25.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
26. 26.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
27. 27.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
28. 28.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 wire has come loose
29. 29.True or false: if the switch is OFF, the circuit is closed and current flows. (a) True (b) False
30. 30.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the filament (c) the glass (d) the base
31. 31.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
32. 32.🔦 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 spoon. Does the bulb glow? (a) Yes (b) No
33. 33.🔁 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
34. 34.🔁 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
35. 35.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
36. 36.🔁 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
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 copper wire. Does the bulb glow? (a) No (b) Yes
38. 38.🔦 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 dry cork. Does the bulb glow? (a) Yes (b) No
39. 39.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
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. Does the bulb glow? (a) Yes (b) No

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