Answer: R = 394.36ohm
Explanation: In a LR circuit, voltage for a resistor in function of time is given by:
![V(t) = \epsilon. e^{-t.\frac{L}{R} }](https://tex.z-dn.net/?f=V%28t%29%20%3D%20%5Cepsilon.%20e%5E%7B-t.%5Cfrac%7BL%7D%7BR%7D%20%7D)
ε is emf
L is indutance of inductor
R is resistance of resistor
After 4s, emf = 0.8*19, so:
![0.8*19 = 19. e^{-4.\frac{22}{R} }](https://tex.z-dn.net/?f=0.8%2A19%20%3D%2019.%20e%5E%7B-4.%5Cfrac%7B22%7D%7BR%7D%20%7D)
![0.8 = e^{-\frac{88}{R} }](https://tex.z-dn.net/?f=0.8%20%3D%20e%5E%7B-%5Cfrac%7B88%7D%7BR%7D%20%7D)
![ln(0.8) = ln(e^{-\frac{88}{R} })](https://tex.z-dn.net/?f=ln%280.8%29%20%3D%20ln%28e%5E%7B-%5Cfrac%7B88%7D%7BR%7D%20%7D%29)
![ln(0.8) = -\frac{88}{R}](https://tex.z-dn.net/?f=ln%280.8%29%20%3D%20-%5Cfrac%7B88%7D%7BR%7D)
![R = -\frac{88}{ln(0.8)}](https://tex.z-dn.net/?f=R%20%3D%20-%5Cfrac%7B88%7D%7Bln%280.8%29%7D)
R = 394.36
In this LR circuit, the resistance of the resistor is 394.36ohms.
In some early mornings , dew drops can be found on grass or a car parked outside, but not on other materials such as the sidewalk because the night -time temperature on grass and the car went below the dew point, but the temperature of the concrete did not drop enough to reach the dew point level
Dew can be formed on any object when the temperature of the object drop. When this happen, the object will be cool which will eventually cool the surrounding air around the object.
Dew drops is as a result of condensation in the air. When the cool air causes the air vapor to convert to liquid. The dew will form when the temperature of the object balances with the dew point in the surrounding environment.
In some early mornings , dew drops can be found on grass or a car parked outside, but not on other materials such as the sidewalk because the night -time temperature on grass and the car went below the dew point, but the temperature of the concrete did not drop enough to reach the dew point level
Therefore the correct option is therefore A
Learn more here : brainly.com/question/13834972
Is the variable you change, independent, I, something I change.
Answer:
- path differnce = 2.18*10^-6
- 1538 lines
Explanation:
- The path difference for the waves that produce the pattern of diffraction, is given by the following formula:
(1)
d: separation between slits = 0.50mm = 0.50*10^-3 m
θ: angle of a diffraction = 0.25°
Then, the path difference is:
![path\ difference\ =(0.50*10^{-3}m)sin(0.25\°)=2.18*10^{-6}m](https://tex.z-dn.net/?f=path%5C%20difference%5C%20%3D%280.50%2A10%5E%7B-3%7Dm%29sin%280.25%5C%C2%B0%29%3D2.18%2A10%5E%7B-6%7Dm)
- The maximum number of bright lines are calculated by using the following formula:
(2)
m: order of the bright
λ: wavelength = 650nm
The maximum bright is calculated for an angle of 90°:
![m=\frac{(0.50*10^{-3}m)sin90\°}{650*10^{-9}m} \approx 769](https://tex.z-dn.net/?f=m%3D%5Cfrac%7B%280.50%2A10%5E%7B-3%7Dm%29sin90%5C%C2%B0%7D%7B650%2A10%5E%7B-9%7Dm%7D%20%5Capprox%20769)
The maxium number of bright lines are twice the previous result, that is, 1538 lines