Question 13 (2 points) To increase power, it is necessary to (2 points)
A)
decrease the work being done and decrease the time in which the work was completed
B)
increase the work being done or decrease the time in which the work is completed
C)
increase the work being done and increase the time in which the work was completed
D)
decrease the work being done and increase the time in which the work is completed

I'm pretty sure the answer to this question is c.

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: