Physics

Problem

A solenoid

60\,\text{cm}

long has a uniform cross-sectional area of

4\,\text{cm}^2

. The first

30\,\text{cm}

contains

3000

turns, while the remaining

30\,\text{cm}

contains

6000

turns. The solenoid is air-cored and carries a current of

3\,\text{A}

. Estimate the total magnetic energy stored within the solenoid. a)

0.17\,\text{J}

3.4\,\text{J}

0.34\,\text{J}

0.68\,\text{J}