Answer:
If a piece of iron is brought near a permanent magnet, the electrons within the atoms in the iron orient their spins to match the magnetic field force produced by the permanent magnet, and the iron becomes “magnetized.”
Explanation:
i dont know how to add align and domain
Answer:

Explanation:
Given data
Current I=82µA=82×10⁻⁶A
Resistance R=2.4×10⁵Ω
to find
Voltage
Solution
From Ohms law we know that:

The answer is c. it requires no works
Answer:
b.
Explanation:
In case of Single Slit, diffraction will occur.
Then In Single slit Diffraction, width of central fringe is

where D= distance b/w screen and slit
a= slit width
\lambda = wavelength
Thus if Screen width increases keeping other factors same then width of central fringe becomes narrower as

On increasing the slit width the central bright fringe width The width of the central bright fringe becomes narrower.