How does a natural ""solar thermostat"" keeps the core fusion rate steady in the sun?

Explanation:

What is solar thermostat?

A solar thermostat automatically regulates temperature of the sun when the temperature reaches a certain point and its also known as gravitational equilibrium.

NOTE: if the core temperature decreases, then the fusion rate decreases and this lowers the pressure and the cause the core to contract and heat up.

Also, the increase in core temperature, increases the fusion rate and this raise the core pressure and this cause the core expands and cools down.

The fusion rate of the sun increase when core is a bit hotter. This increase in the rate of fusion produces more energy, which cause the core to expand slightly and cool.

The fusion rate is then slow down due to the cooling until the sun get back to it's original size and temperature. The fusion that occur in the sun concerts hydrogen into helium, energy and neutrinos.

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: