Question

Yakub made a circuit . He observed that the bulb did not glow , but on bringing a compass needle near it shows deflection. He was quite confused that if current is flowing through the circuit then why the bulb is not glowing. Meanwhile his friend Sourav arrived and suggested that he add one more cell in the circuit. The bulb, then started glowing.

(a) What does the deflection of a compass needle show?
(b) Why the bulb did not glow in the first case but glow in the second case?
(c) Do distilled water conduct electricity? What will happen if we add sugar to it and then salt to it? Explain.

Answer 1

The compass needle deflection indicated a weak electric current presence not sufficient to light the bulb; increasing voltage with an additional cell led to the bulb glowing. Distilled water does not conduct electricity; it does when ions are present after dissolving salt.

Step-by-step explanation:

The deflection of a compass needle indicates the presence of a magnetic field, which is created by electric currents flowing through a conductor. In Yakub's case, this deflection confirmed that some current was indeed flowing, but it wasn't strong enough to light the bulb. On adding one more cell to the circuit, the voltage increased, providing enough current to light the bulb, demonstrating that the aggregate voltage was initially too low to overcome the bulb's resistance.

Distilled water does not conduct electricity because it lacks free ions. Adding sugar to distilled water does not result in electrical conductivity because sugar dissolves as uncharged molecules. However, adding salt, which dissolves into ions, allows the water to conduct electricity because the ions are mobile charged particles that complete the circuit, allowing the light bulb to glow.