Answer:
minimum thickness of the coating = 122.868 nm
Explanation:
Given data
lens index of refraction = 1.29
wavelength = 634 nm
glass index of refraction = 1.53
to find out
minimum thickness of the coating
solution
we have given non reflective coating
so
we know that minimum thickness of the coating formula
minimum thickness of the coating = Wavelength / 4n
here n is coating index of refraction
so put here both value to get thickness
minimum thickness of the coating = Wavelength / 4n
minimum thickness of the coating = 634 / 4 ( 1.29 )
so minimum thickness of the coating = 122.868 nm
C. Thick wire and cold temperature.
Explanation:
The resistance of a wire is given by: R = (ρL)/A
where ρ is the resistivity of the material, L is the length of the wire, A is the cross-sectional area of the wire.
From the formula, we see that the thicker the wire, the larger A, therefore the smaller the resistivity. so, a thick wire will have lower resistivity.
Moreover, the resistance of a wire increases with the temperature. In fact, high temperatures mean more motion of the atoms/electrons inside the wire, so more resistance to the flow of current through it. Therefore, colder temperature means lower resistance.
So, the correct option is thick wire and cold temperature.
The density of the object is the ratio of its mass and volume. From the given dimensions above, we determine the volume through the equation,
V = L x W x H
Substituting,
V = (3 cm)(2 cm)(1 cm) = 6 cm³
From the idea presented above,
d = m/V
Substituting the known values,
d = (30 g)/ (6 cm³) = 5 g/cm³
ANSWER: 5 g/cm³
The derived unit for voltage is named volt.
As per energy conservation in the reversible engine we can say
here we know that
now from above equation
now we can convert it into kW
so above is the power input to the refrigerator
now to find COP we know that
so COP of refrigerator is 2.2
