Answer:

Explanation:
When the unpolarized light passes through the first polarizer, only the component of the light parallel to the axis of the polarizer passes through.
Therefore, after the first polarizer, the intensity of light passing through it is halved, so the intensity after the first polarizer is:

Then, the light passes through the second polarizer. In this case, the intensity of the light passing through the 2nd polarizer is given by Malus' law:

where
is the angle between the axes of the two polarizer
Here we have

So the intensity after the 2nd polarizer is

And substituting the expression for I1, we find:

Answer:
a. 0.000002 m
b. 0.00000182 m
Explanation:
36 cm = 0.36 m
15 cm = 0.15 m
a) We can start by calculating the air-water pressure of the bucket submerged 20m below the water surface:

Suppose air is ideal gas, then if the temperature stays the same, the product of its pressure and volume stays the same

Where P1 = 1.105 Pa is the atmospheric pressure, V_1 is the air volume in the bucket on the suface:

As the pressure increases, the air inside the bucket shrinks. But the crossection area stays constant, so only h, the height of air, decreases:


b) If the temperatures changes, we can still reuse the ideal gas equation above:


Answer:
When the compass is placed below the wire, and the electric current switched on, the needle deflects in the opposite direction. If an electric current is passed through a long coil of wire (a solenoid ) a magnetic field is produced which is the same shape as that of a bar magnet.
Explanation:
Answer:
Ideal machines are said to have parts which are weightless , frictionless and strings if any are inextensible. Practical machines have parts which have weights, friction and it causes some loss of work done. So these are the differences between Ideal Machine and Practical Machines.