Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 564 · 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 closed and current flows. (a) False (b) True
2. 2.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
3. 3.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) a wire has come loose
4. 4.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
5. 5.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
6. 6.🔦 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) Yes (b) No
7. 7.Which of these means the circuit is open? (a) a cell is taken out (b) the switch is ON (c) all wires are joined (d) the loop is complete
8. 8.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
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 ceramic cup. Does the bulb glow? (a) Yes (b) No
10. 10.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
11. 11.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
12. 12.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is OFF (c) all wires are joined (d) a wire has come loose
13. 13.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) only one (c) both of them (d) it does not matter
14. 14.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
15. 15.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a complete loop (d) a broken path
16. 16.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
17. 17.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
18. 18.🔦 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 an iron nail. Does the bulb glow? (a) Yes (b) No
19. 19.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
20. 20.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
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 metal paper clip. Does the bulb glow? (a) Yes (b) No
22. 22.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
23. 23.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the filament (b) the switch (c) the base (d) the glass
24. 24.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a closed circuit (c) an open circuit (d) a series circuit
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 copper wire. Does the bulb glow? (a) Yes (b) No
26. 26.Which of these means the circuit is closed? (a) the switch is ON (b) a cell is taken out (c) a wire has come loose (d) the bulb is unscrewed
27. 27.🔦 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 graphite rod. Does the bulb glow? (a) No (b) Yes
28. 28.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
29. 29.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
30. 30.🔦 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) Yes (b) No
31. 31.🔦 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
32. 32.True or false: if the switch is ON, the circuit is open and no current flows. (a) True (b) False
33. 33.🔦 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) Yes (b) No
34. 34.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) the switch is OFF
35. 35.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
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. A gap in one wire is bridged by a graphite rod. Does the bulb glow? (a) Yes (b) No
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 graphite rod. Does the bulb glow? (a) Yes (b) No
38. 38.Which of these means the circuit is closed? (a) a wire is cut (b) a cell is taken out (c) the loop is complete (d) the switch is OFF
39. 39.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
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 safety pin. Does the bulb glow? (a) Yes (b) No

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