Answer:
(a) B = 5.6 micro Tesla
Explanation:
Current in the wire, i = 140 A
distance, r = 5 m
The formula for the magnetic field at a distance r due to the current carrying wire


B = 5.6 x 10^-6 Tesla
B = 5.6 micro Tesla
(b) As the magnetic field of earth at this site is 20 micro tesla so the magnetic field due to current carrying wire interfere the magnetic compass.
Mars: 0.38
weight = mass x surface gravity
multiplying your weight on Earth by the number above will give you your weight on the surface of Mars
If you weigh 150 pounds (68 kg.) on Earth, you would weigh 57 lbs. (26 kg.) on Mars
Explanation:
Understanding that stars are naturally quite hot, imagine I pulled a piece of hot iron from a furnace. It would glow a bright red, and then slowly fade to black as the iron cools.
White dwarfs glow for the same reason - they are HOT!
Answer:
Explanation:
Given
Initial Intensity of light is S
when an un-polarized light is Passed through a Polarizer then its intensity reduced to half.
When it is passed through a second Polarizer with its transmission axis 

here 


When it is passed through third Polarizer with its axis
to first but
to second thus 



When middle sheet is absent then Final Intensity will be zero