To solve this problem we will apply the concepts related to the balance of forces. Said balance will be given between buoyancy force and weight, both described as derived from Newton's second law, are given as
Buoyancy force

Here,
V = Volume
=Density of air
g = Acceleration due to gravity
Weight

m = mass
g = Gravity
Our values are given as,




Then,

Replacing,

Now net force is ,

Mass of the sphere is

Now acceleration of the sphere is



Therefore the acceleration of the sphere as it falls through water is 
The density would decrease because the mass of an object deals with the amount of atoms in the object and since none of the object was reduced "a" wouldn't be the answer. Depending on the amount and period of time that the heat is applied the liquid could change into a gas so "d" wouldn't be correct. Density is the mass÷ volume, and when you add heat to an object it could take up different amounts of space because of its particles gaining energy and spreading apart. So the density would decrease because of the volume increasing. So I believe that "c" is the answer.
Explanation:
(a) We have,
Length of solenoid, l = 55 cm = 0.55 m
Diameter of the solenoid, d = 10 cm
Radius, r = 5 cm = 0.05 m
Number of loops in the solenoid is 1000.
(a) The self inductance in the solenoid is given by :

A is area

(b) The energy stored in the inductor is given by :

Hence, this is the required solution.
Answer: I belive that the Answer is C.) Conduction
Explanation:
i thinks answers is gap relutance increases linearly with magnetic density