Answer:
option E
Explanation:
Given,
Length of the solenoid = 0.50 m
Number of turn = 1000 turn
radius, r = 4 cm
Current = 18 A
Magnetic field inside the solenoid.
[tex]B = \mu_0 NI[/tex]
[tex]B = \mu_0 (\dfrac{N}{L})I[/tex]
[tex]B = 4\pi \times 10^{-7}\times (\dfrac{1000}{0.5})\times 18[/tex]
[tex]B = 0.045\ T[/tex]
[tex]B = 45\ mT[/tex]
Hence, the correct answer is option E