For this case we have that by definition, physical power refers to the amount of work done for a unit of time.
So:
Where:
W: It's the work
t: It's time
The power units are in
So, according to the problem data we have:
Clearing the work of the formula:
Thus, the work is 1200 joules.
Answer:
Option C
Answer:
Explanation:
a)
Using Ohms Law
Where J is the current density
and the direction of E is the same as the direction of the current. Since J is uniform throughout the conductor just inside at a radius a (and anywhere else).
b)
Since we have no changing electric fields we can use Ampere’s law in it’s simplest form without displacement current
such that
and by the right hand rule, since the current is going to the right, the magnetic field is circling around the conductor such that it’s pointing out of the page at the top and into the page at the bottom.
c)
The Poynting vector is given by
and by the right hand rule it’s always pointing in towards the center of the conductor.
d)
Note: directions of these three vectors are mentioned along with their magnitudes in above 3 parts a , b and c
Answer:
Explanation:
Let the angle between the first polariser and the second polariser axis is θ.
By using of law of Malus
(a)
Let the intensity of light coming out from the first polariser is I'
.... (1)
Now the angle between the transmission axis of the second and the third polariser is 90 - θ. Let the intensity of light coming out from the third polariser is I''.
By the law of Malus
So,
(b)
Now differentiate with respect to θ.