Answer:
Please refer to the figure.
Explanation:
The crucial point here is to calculate the enclosed current. If the current I is flowing through the whole cross-sectional area of the wire, the current density is

The current density is constant for different parts of the wire. This idea is similar to that of the density of a glass of water is equal to the density of a whole bucket of water.
So,

This enclosed current is now to be used in Ampere’s Law.

Here,
represents the circular path of radius r. So we can replace the integral with the circumference of the path,
.
As a result, the magnetic field is

Explanation:
The force of the roller-coaster track on the cart at the bottom is given by :
, m is mass of roller coaster
Case 1.
R = 60 m v = 16 m/s

Case 2.
R = 15 m v = 8 m/s

Case 3.
R = 30 m v = 4 m/s

Case 4.
R = 45 m v = 4 m/s

Case 5.
R = 30 m v = 16 m/s

Case 6.
R = 15 m v =12 m/s

Ranking from largest to smallest is given by :
F>E>A=B>C>D
Option (D) is correct that all of the above are physical properties of non metals.
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Answer:b
Explanation:
Object will be stable if its center of gravity lies over its base of support.
If the center of gravity is above the center of buoyancy then it provides positive righting moment and the object floats over the liquid and such object is said to possess positive meta-centric height.