The aberration of starlight proved the central idea of: (a) copernicus's heliocentric cosmos (b) kepler's 4th law of orbital motion (c) eratosthenes' measurement of earth's circumference (d) newton's law of gravity (e) galileo's theory of the moon's phases

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

correct it is c.) b b

the electric field is a “force field” around a charged object that illustrates the direction the electric force would push an imaginary 

come closer and become far apart and become steam/gas