Solenoid 2 has twice the radius and six times the number of turns per unit length as solenoid 1. The ratio of the magnetic field in the interior of 2 to that in the interior of 1 is:
A) 2
B) 4
C) 6
D) 1
E) 1/3

Question

Quizplus · Accepted Answer

The magnetic field inside a solenoid is directly proportional to the number of turns per unit length and independent of the radius. Since solenoid 2 has six times the number of turns per unit length, the magnetic field inside it is six times that of solenoid 1.

Solenoid 2 Has Twice the Radius and Six Times the Number