Metals in general, are good heat conductors

The magnitude of the average emf induced in the loop is given by (we ignore the signs since we are interested only in the magnitude)

where

is the variation of magnetic flux through the area enclosed by the loop, and

is the time interval.

The magnetic flux is given by

where B is the intensity of the magnetic field, A is the area enclosed by the loop and

is the angle between the perpendicular to the area and the magnetic field. In our problem, this angle is zero because the loop is perpendicular to the magnetic field, so the cosine is 1. The area of the loop is fixed, and it is

where

is the radius of the loop. The only element which is variable in the formula is B, which changes from 0.069 T to -0.044 T (opposite direction). So we can rewrite the flux variation as

where

By using

, we can find the magnitude of the emf induced:

**Answer:**

**Explanation:**

It is given that,

Force due to rope 1,

Force due to rope 2,

**Let is the angle must a third rope tension be applied in order to keep the boat at rest. It can be given by :**

The angle clockwise from the positive x-axis will be equal to,

**So, the angle must a third rope tension be applied in order to keep the boat at rest is 156.81 degrees. Hence, this is the required solution.**

What is the value of the voltage? There must be one somewhere.

This might be too simple minded, but I'll give it a voltage of 10 Volts.

R = voltage / Current

R = 10 / 0.5

R = 20 volts.

Perhaps you could post a diagram if this is a Kirchhoff Law Question.