Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 412 · 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.🔦 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
2. 2.Which of these means the circuit is open? (a) all wires are joined (b) a cell is taken out (c) the switch is ON (d) the loop is complete
3. 3.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a plastic gap (d) a complete loop
4. 4.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
5. 5.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a full circuit (d) a series circuit
6. 6.🔦 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
7. 7.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
8. 8.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the loop is complete (c) the switch is OFF (d) a wire has come loose
9. 9.True or false: if a wire is cut, the circuit is open and no current flows. (a) True (b) False
10. 10.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
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.🔦 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) Yes (b) No
13. 13.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
14. 14.🔁 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) both of them (d) only one
15. 15.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
16. 16.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the glass (c) the filament (d) the switch
17. 17.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
18. 18.Which of these means the circuit is closed? (a) a wire has come loose (b) the switch is OFF (c) a wire is cut (d) the switch is ON
19. 19.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire has come loose (c) a cell is taken out (d) all wires are joined
20. 20.🔦 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
21. 21.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
22. 22.🔦 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
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 plastic straw. Does the bulb glow? (a) No (b) Yes
24. 24.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
25. 25.Which of these means the circuit is open? (a) a wire has come loose (b) the switch is ON (c) the loop is complete (d) all wires are joined
26. 26.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
27. 27.🔦 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
28. 28.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
29. 29.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 switch is OFF
30. 30.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
31. 31.🔦 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) No (b) Yes
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 cotton thread. Does the bulb glow? (a) No (b) Yes
33. 33.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
34. 34.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
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. A gap in one wire is bridged by a rubber eraser. Does the bulb glow? (a) No (b) Yes
36. 36.🔦 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
37. 37.Which of these means the circuit is open? (a) a wire is cut (b) all wires are joined (c) the switch is ON (d) the loop is complete
38. 38.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
39. 39.🔦 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 copper wire. Does the bulb glow? (a) Yes (b) No
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 ceramic cup. Does the bulb glow? (a) Yes (b) No

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