Answer:
The current pass through the coil is 6.25 A
Explanation:
Given that,
Diameter = 25 cm
Magnetic field = 1.0 mT
Number of turns = 100
We need to calculate the current
Using the formula of magnetic field


Where, N = number of turns
r = radius
I = current
Put the value into the formula


Hence, The current passes through the coil is 6.25 A
Answer:
2.5 cm
40 D
Explanation:
When the radius of curvature of a lens is divided by 2 we get the focal length of the lens.
Focal length is given by

The focal length of the lens is 2.5 cm
When we divide 1 by the focal length in the unit of meters we get the power of a lens
Power of a lens is given by

The power of the lens is 40 D
Answer:
Explanation:
This does not violate Newton's 1st law because the net force would still be 0 in order to produce uniform motion (aka constant velocity). The other forces acting on the vehicles is air resistance which is non-zero. So we need car internal force to counter balance this force, which require extra gas for the car.
There are some missing data in the problem. The full text is the following:
"<span>A </span>real<span> (</span>non-Carnot<span>) </span>heat engine<span>, </span>operating between heat reservoirs<span> at </span>temperatures<span> of 710 K and 270 K </span>performs 4.1 kJ<span> of </span>net work<span>, and </span>rejects<span> 9.7 </span>kJ<span> of </span>heat<span>, in a </span>single cycle<span>. The </span>thermal efficiency<span> of a </span>Carnot heat<span> engine, operating between the same </span>heat<span> reservoirs, in percent, is closest to.."
Solution:
The efficiency of a Carnot cycle working between cold temperature </span>

and hot temperature

is given by

and it represents the maximum efficiency that can be reached by a machine operating between these temperatures. If we use the temperatures of the problem,

and

, the efficiency is

Therefore, the correct answer is D) 62 %.
Answer: Its in explanation.
Explanation:
Because the electroscope is made from conducting material, some of its electrons move up to the top of the electroscope to be near the charged rod when the rod is held close.