How is a rock defined? ...

[dmcintosh]

How is a rock defined?

Question 2

A solenoidal inductor for a printed circuit board is being redesigned. To save weight, the number of turns is reduced by one-half, with the geometric dimensions kept the same. By how much must the current change if the energy stored in the inductor is to remain the same?
  1.It must be four times larger.
  2.It must be two times larger.
  3.It should be left the same.
  4.It should be one-half as large.
  5.No change in the current can compensate for the reduction in the number of turns.

[lou]

Answer to Question 1

A rock is any naturally occurring, solid mineral mass that makes up part of Earth's
lithosphere.

Answer to Question 2

2