Electronics Worksheet: Simple Circuit – Open and Closed

Electronics lesson 4: Open and closed circuits · Set 896 · 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.Which of these means the circuit is closed? (a) a cell is taken out (b) all wires are joined (c) a wire is cut (d) the bulb is unscrewed
2. 2.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
3. 3.🔦 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) No (b) Yes
4. 4.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
5. 5.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
6. 6.🔦 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 brass key. Does the bulb glow? (a) No (b) Yes
7. 7.🔦 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
8. 8.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 loop is complete
9. 9.🔦 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) Yes (b) No
10. 10.Which of these means the circuit is open? (a) the bulb is unscrewed (b) all wires are joined (c) the loop is complete (d) the switch is ON
11. 11.🔦 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
12. 12.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) an open circuit (d) a full circuit
13. 13.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
14. 14.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
15. 15.Which of these means the circuit is open? (a) a cell is taken out (b) the loop is complete (c) the switch is ON (d) all wires are joined
16. 16.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) a wire is cut
17. 17.🔁 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
18. 18.🔦 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
19. 19.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the filament (d) the base
20. 20.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
21. 21.True or false: if the switch is OFF, the circuit is open and no current flows. (a) True (b) False
22. 22.🔦 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
23. 23.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
24. 24.🔁 What must there be for a current to flow? (a) one loose end (b) a broken path (c) a complete loop (d) a plastic gap
25. 25.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
26. 26.Which of these means the circuit is open? (a) the switch is ON (b) the switch is OFF (c) all wires are joined (d) the loop is complete
27. 27.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
28. 28.🔦 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
29. 29.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
30. 30.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) a wire has come loose (d) the loop is complete
31. 31.True or false: if the bulb is unscrewed, the circuit is open and no 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 closed? (a) a wire is cut (b) the switch is OFF (c) the switch is ON (d) a cell is taken out
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 rubber band. Does the bulb glow? (a) Yes (b) No
35. 35.🔦 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
36. 36.🔦 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
37. 37.🔦 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
38. 38.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
39. 39.🔦 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
40. 40.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No

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