A solenoid is 2.50 cm in diameter and 30.0 cm long. It has 300 turns and carries 12 A. (a) Calculate the magnetic field inside the solenoid. (b) Calculate the magnetic flux through the surface of a circle of radius 1.00 cm, which is positioned perpendicular to and centered on the axis of the solenoid. (c) The perimeter of this circle is made of conducting material. The current in the solenoid uniformly goes from 12 A to 10 A in 0.001 seconds. What e. M.F. Is generated in the conducting material? (d) Now, inside the solenoid we put a bar of steel, a ferromagnetic material. Steel has got a magnetic permeability μm = 4000μ0 . If the current in the solenoid is 12 A, what's the total magnetic field in the steel bar?

On a horizontal frictionless surface, a small block with mass 0.200 kg has a collision with a block of mass 0.400 kg. immediately after the collision, the 0.200 kg block is moving at 12.0 m/s in the direction 30° north of east and the 0.400 kg block is moving at 11.2 m/s in the direction 53.1° south of east. use coordinates where the +x-axis is east and the +y-axis is north.(a) what is the total kinetic energy of the two blocks after the collision (in ) what is the x-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your ) what is the y-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your answer.)

Why should the wavelength scale of spectroscope be calibrated

3. which is not a primary color of light? blue red green yellow