Ahorizontal beam of light of intensity 25 w/m2 is sent through two polarizing sheets. the polarizing direction of the first makes a 15° angle with that of the second. suppose that the initial beam is unpolarized. what then is the intensity of the transmitted light? a. 7.2 w/m2 b. 11.7 w/m2 c. 12.1 w/m2 d. 23.3 w/m e. 24.1 w/m

option (B)

Explanation:

Intensity of unpolarised light, I = 25 W/m^2

When it passes from first polarisr, the intensity of light becomes

Let the intensity of light as it passes from second polariser is I''.

According to the law of Malus

Where, θ be the angle between the axis first polariser and the second polariser.

I'' = 11.66 W/m^2

I'' = 11.7 W/m^2

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: