Hi there!
Angular momentum is equivalent to:

L = angular momentum (kgm²/s)
I = moment of inertia (kgm²)
ω = angular velocity (rad/sec)
Plug in the given values for moment of inertia and angular speed:

Answer:
a)
b) north edge will rise up
Explanation:
torque on the coil is given as

where N is number of loop = 9 loops
i is current = 7.80 A
-B -earth magnetic field = 
A- area of circular coil


A =0.015 m2
PUTITNG ALL VALUE TO GET TORQUE


b) north edge will rise up
Answer:d. Ground waves
Explanation:A P-wave is one of the two main types of seismic waves. P-waves travel faster than other seismic waves and hence are the first signal from an earthquake to arrive at any affected location or at a seismograph
<span>Whenever I have problems with the magnetic field strength of an electromagnet people tell to use a finer wire, I have some, its thickness is not more then the thickness of a hair, but whenever I use it, I have difficulty in connecting it with the battery because it's so thin it easily breaks off, and when I turn on the switch, it burns up instantly, maybe I am not using enough length of it.</span>