In the above case we can say that power given by external agent to pull the rod must be equal to the power dissipated in the form of heat due to magnetic induction.
Part a)
when we pull the rod with constant speed then power required will be product of force and velocity
here we will have

P = 4 W
v = 4 m/s
now we will have


So external force required will be 1 N
PART B)
now in order to find magnetic field strength we can say

here we know that induced EMF in the wire is E = vBL
so power due to induced magnetic field is given by


by solving above equation we will have

Answer:
33.61°
Explanation:
Refractive index is equal to velocity of the light 'c' in empty space divided by the velocity 'v' in the substance.
Or ,
n = c/v.
v is the velocity in the medium (2.3 × 10⁸ m/s)
c is the speed of light in air = 3.0 × 10⁸ m/s
So,
n = 3.0 × 10⁸ / 2.3 × 10⁸
n = 1.31
Using Snell's law as:
Where,
is the angle of incidence ( 25.0° )
is the angle of refraction ( ? )
is the refractive index of the refraction medium (air, n=1)
is the refractive index of the incidence medium (glass, n=1.31)
Hence,
Angle of refraction =
= 33.61°
The correct response is B .
Answer:
plz give example so we are able to answer you
Explanation: