In electromagnetic waves, frequency is inversely proportional to
2 answers:
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Answer:
the correct answer is C, E’= 4E
Explanation:
In this exercise you are asked to calculate the electric field at a given point
E =
indicates that the field is E for r = 2m
E = (1)
the field is requested for a distance r = 1 m
E ’= k \frac{q}{r'^2}
E ’= k q / 1
from equation 1
4E = k q
we substitute
E’= 4E
so the correct answer is C
Answer:
Q = +1.4 pC
Explanation:
- The capacitance of any capacitor, by definition, is as follows:
-
- Applying Gauss'Law and the definition of electric potential, it can be showed that the capacitance of a parallel-plate capacitor can be expressed as follows:
-
- Where εr is the dielectric constant of the material that fills the space between the plates, A is the area of one of the plates, and d, is the separation between them.
- Replacing by the givens in (2) we can find the value of the capacitance C, as follows:
- Replacing the values of C and V in (1), we can solve for Q, as follows:
- As the outer surface is at a higher potential that the inside surface, the charge on it must be positive, and is equal to +1.4 pC.
Answer:
<em>Heat of the reservoir is 461.38 K or 188.1 °C</em>
<em>The heating load is 18.705 kW</em>
Explanation:
COP = 8.7
working temperature = 248 °C = 248 + 273.3 = 521.3 K
work power W = 2.15 kW
reservoir temperature = ?
heating load Q = ?
We know that
COP = Q/W
Q = COP x W = 8.7 x 2.15 = <em>18.705 kW</em>
Also,
COP = =
8.7 =
4535.31 - 8.7 = 521.3
4535.31 - 521.3 = 8.7
4014.01 = 8.7
= 4014.01/8.7 = <em>461.38 K</em>
or 461.38 -273.3 = <em>188.1 °C</em>