Answer: A.The total number of energy levels the electron can jump to.
Explanation:
Spectral lines are bright or dark lines over continuous spectrum which occur due to emission or absorption of energy.
When an electron jumps to or from one energy level to another energy level, spectral lines are produced. The range of spectral lines depends on the number of energy levels available to which the electron can jump. This depends the amount of energy gained/lost by the electron.
Thus, the correct answer is: A.The total number of energy levels the electron can jump to.
Answer: Letter X in the diagram represent the angle of incidence
Explanation: One of the properties of wave is reflection. But before reflection can occur, there must have been a directed motion of wave particle towards a plane surface. The angle of incidence is the angle between the direction of motion of the wave particle ( for example; light) and the normal to the plane surface.
Answer:
the wavelength λ of the light when it is traveling in air = 560 nm
the smallest thickness t of the air film = 140 nm
Explanation:
From the question; the path difference is Δx = 2t (since the condition of the phase difference in the maxima and minima gets interchanged)
Now for constructive interference;
Δx= 
replacing ;
Δx = 2t ; we have:
2t = 
Given that thickness t = 700 nm
Then
2× 700 =
--- equation (1)
For thickness t = 980 nm that is next to constructive interference
2× 980 =
----- equation (2)
Equating the difference of equation (2) and equation (1); we have:'
λ = (2 × 980) - ( 2× 700 )
λ = 1960 - 1400
λ = 560 nm
Thus; the wavelength λ of the light when it is traveling in air = 560 nm
b)
For the smallest thickness 
∴ 



Thus, the smallest thickness t of the air film = 140 nm
Answer:
-34.5 W
Explanation:
rate of heat transfer = Stefan-Boltzmann constant x emissivity x surface area x temperature^4

Answer:
P = 24.32 W
Explanation:
The question is, "Two resistors 5 Ω and 10 Ω are connected in parallel with a 9 V power supply. Calculate the output power of the power supply.".
The voltage of the power supply, V = 9 V
Resistor 1, R₁ = 5 Ω
R₂ = 10 Ω
The equivalent of parallel combination of resistors is given by :

The power of the output is given by :

So, the output power is equal to 24.32 W.