Answer:
Current, I = 1000 A
Explanation:
It is given that,
Length of the copper wire, l = 7300 m
Resistance of copper line, R = 10 ohms
Magnetic field, B = 0.1 T
Resistivity,
We need to find the current flowing the copper wire. Firstly, we need to find the radius of he power line using physical dimensions as :
r = 0.00199 m
or
The magnetic field on a current carrying wire is given by :
I = 1000 A
So, the current of 1000 A is flowing through the copper wire. Hence, this is the required solution.
Answer:
1.21
Explanation:
Heat rise in the body happens due to heat supplied by water to the body.
Heat rise in body = m₁ c₁ ΔT₁
Where m₁ is mass of body and c₁ is its specific heat of body
Heat lost from water to the body = m₂ c₂ ΔT₂
Where m₂ is mass of water and c₂ is its specific heat of water ( c₂ =1 (since water))
Equating both:
15.3 x c₁ x 4.3 = 80.2 x 1 x 4.3
⇒ c₁ = 80.2 / (15.3 x 4.3) = 1.21
The frictional force is in the opposite direction