Answer:
The current in the coil is 4.086 A
Explanation:
Given;
radius of the circular coil, R = 2.5 cm = 0.025 m
number of turns of the circular coil, N = 740 turns
magnetic field at the center of the coil, B = 0.076 T
The magnetic field at the center of the coil is given by;

where;
μ₀ is permeability of free space = 4 x 10⁻⁷ m/A
I is the current in the coil
R is radius of the coil
N is the number of turns of the coil
The current in the circular coil is given by

Therefore, the current in the coil is 4.086 A
A) Expanding. We know this because it has a similar effect with sound. When a car goes by the pitch gets deeper and deeper. It's because you're receiving less waves. Same thing for light but instead of a pitch it's light, and the farther spread the waves - the redder, the closer and more contracted - the bluer
Cell are small and us human can't see them with our own eyes. it is in possible to see cell without a microscope
Answer:
0.2129 mm
Explanation:
We have given volume of the paint = 1 gallon
Area that covers the paint 
We have to find the thickness of the fresh paint
So
So the thickness of fresh paint on the wall is 0.2129 mm
Answer:
B. Maximum velocity of ejected electrons.
Explanation:
The ejection of electrons form a metal surface when the metal surface is exposed to a monochromatic electromagnetic wave of sufficiently short wavelength or higher frequency (or equivalently, above a threshold frequency), which leads to the enough energy of the wave to incident and get absorbed to the exposed surface emits electrons. This phenomenon is known as the photoelectric effect or photo-emission.
The minimum amount of energy required by a metal surface to eject an electron from its surface is called work function of metal surface.
The electrons thus emitted are called photo-electrons.
The current produced as a result is called photo electricity.
Energy of photon is given by:

where:
h = Planck's constant
frequency of the incident radiation.