A device called a flip coil can be used to measure the earth's magnetic field. The coil has 180 turns and an area of 1.5×10−2 m2. It is oriented with its plane perpendicular to the earth's magnetic field, then flipped 180 degrees so the field goes through the coil in the opposite direction. The earth's magnetic field is 8.0×10−2 mT , and the coil flips over in 0.20 s .

What is the average value of the emf induced in the coil during the time it is flipping?
(a) 0.54 mV
(b) 1.1 mV
(c) 2.2 mV
(d) 11 mV

Explanation:

Change in flux =

magnetic field x area of cross section x no of turns x 2

8 x 10⁻² x 10⁻³ 1.5 x 10⁻² x 180 x 2 Weber

= 4320 x 10⁻⁷

Rate of change of flux

= 4320 x 10⁻⁷ /.2

= 21600 x 10⁻⁷

2.16 x  10⁻³

2.16 mV

2.2 mV

no

sodium is solid at rt

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.