Consider a thin walled hoop of uniform material. two axis go through the center of the hoop. one axis is perpendicular to the plane of the hoop and the other axis is parallel to the plane of the hoop. which axis would make the large moment of inertia for the hoop

Explanation:

Moment of Inertia about an axis passing through its center and Perpendicular to its Plane is given by

As all the mass is at radius therefore its moment of inertia is more than the moment of inertia about a axis parallel to the Plane

According to perpendicular axis theorem

and is same due to symmetry

thus

thus Perpendicular z axis will have more moment of inertia

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: