Gain in decibels is given by;
Gain db = 10*log (Po/Pi), where Po = Power output, Pin = Power input
Substituting;
Gain in db = 10 * log (50/5) = 10 db
I’ve done this before the answer is B
The object is at rest is the answer.
I think your question should be:
An industrial laser is used to burn a hole through a piece of metal. The average intensity of the light is
![S = 1.23*10^9 W/m^2](https://tex.z-dn.net/?f=%20S%20%3D%201.23%2A10%5E9%20W%2Fm%5E2%20)
What is the rms value of (a) the electric field and
(b) the magnetic field in the electromagnetic wave emitted by the laser
Answer:
a) ![6.81*10^5 N/c](https://tex.z-dn.net/?f=%206.81%2A10%5E5%20N%2Fc%20)
b) ![2.27*10^3 T](https://tex.z-dn.net/?f=%202.27%2A10%5E3%20T%20)
Explanation:
To find the RMS value of the electric field, let's use the formula:
![E_r_m_s = sqrt*(S / CE_o)](https://tex.z-dn.net/?f=%20E_r_m_s%20%3D%20sqrt%2A%28S%20%2F%20CE_o%29)
Where
;
;
![S = 1.23*10^9 W/m^2](https://tex.z-dn.net/?f=%20%20S%20%3D%201.23%2A10%5E9%20W%2Fm%5E2%20)
Therefore
![E_r_m_s = sqrt*{(1.239*10^9W/m^2) / [(3.00*10^8m/s)*(8.85*10^-^1^2C^2/N.m^2)]}](https://tex.z-dn.net/?f=%20E_r_m_s%20%3D%20sqrt%2A%7B%281.239%2A10%5E9W%2Fm%5E2%29%20%2F%20%5B%283.00%2A10%5E8m%2Fs%29%2A%288.85%2A10%5E-%5E1%5E2C%5E2%2FN.m%5E2%29%5D%7D%20)
![E_r_m_s= 6.81 *10^5N/c](https://tex.z-dn.net/?f=%20E_r_m_s%3D%206.81%20%2A10%5E5N%2Fc%20)
b) to find the magnetic field in the electromagnetic wave emitted by the laser we use:
;
;
![B_r_m_s = 2.27*10^3 T](https://tex.z-dn.net/?f=%20B_r_m_s%20%3D%202.27%2A10%5E3%20T%20)
1: only half the outlet is switched and the lamp is in the other half
2: the lamp is turned off.
3: The light bulb is burned out
4: the switch might be broken
5: the fuse might be blown
6: the electricity might be off