Answer:
The difference between the cost of operating LED and incandescent bulb is $5.1
Explanation:
We are given the cost of electricity that is 12.75 cents per kWh. We want to find out the difference in the operating cost of an incandescent and LED bulb for a time period of 2,000 hours.
Since we are not given the rating of the incandescent bulb and LED bulb, we will assume their ratings.
For a light intensity of 250 Lumens;
The average rating of an LED bulb is approximately 5 Watts.
The average rating of an incandescent bulb is approximately 25 Watts.
Now lets find out the kWh of each bulb.
Energy = Power×Time
For LED bulb:
E = 5×2,000 = 10,000 Wh
Divide by 1000 to convert into kWh
E = 10,000/1000 = 10 kWh
Cost = 12.75×10 = 127.5 cents
Cost = $1.27
For Incandescent bulb:
E = 25×2,000 = 50,000 Wh
Divide by 1000 to convert into kWh
E = 50,000/1000 = 50 kWh
Cost = 12.75×50 = 637.5 cents
Cost = $6.37
Difference in Cost:
Difference = $6.37 - $1.27 = $5.1
Therefore, the difference between the cost of operating LED and incandescent bulb is $5.1.
Answer:
A) Periodic time
Explanation:
Wavelength is the distance from a point on a wave to the same point on an adjacent wave
Wave speed is the speed the wave is travelling at
Wave frequency is how many waves pass a fixed point in a given time period
Answer:
Explanation:
The two media must have differing index of refraction.
Index of refraction is an indication of how fast light can move through the media.
If a light wave approaches an interface at an angle and the media the light is moving into has a higher index of refraction meaning slower light speed in the media, then the part of the wave front hitting first gets slowed down sooner. As each section of the wave front crosses the interface, the whole wave front has changed direction toward the side with the first drag. Much like a column of marching soldiers executing a slight turn each at the precise moment to keep both columns and lined up in "military precision"
If the media the light is moving into has a smaller index of refraction, meaning higher light speed, then the side of the light beam hitting the interface first speeds up before the opposite side of the beam. This makes the angle leaving the interface much closer to the interface surface than the angle inside the higher index media. There becomes a point called the critical angle where the light cannot exit the higher index of refraction and the condition of total internal reflection exists. Think fiber optic cable which can transmit signals hundreds of miles without significant loss.
Answer:
Explanation:
Magnetic flux is expressed as the product of magnetic field and cross sectional area.
Φ = BAsintheta
Given
B = 0.72T
A = 8.2cm×14cm
A = 0.082m × 0.14m
Area = 0.01148m²
Theta = 90°
Substitute into the formula
Φ = BAsintheta
Φ = 0.72(0.01148)sin90°
Φ = 0.72(0.01148)(1)
Φ = 0.0082656
Hence the magnetic flux through the loop is 8.2656 × 10^-3 Weber
Answer:
change in entropy is 3.3034 × 
Explanation:
give data
thermal energy Q = 155 J
temperature T = 340 K
to find out
change in entropy
solution
we know change in entropy formula that is
change in entropy = Q / ( K×T ) ..............1
here K is boltzmann constant that is 1.38 × 
kg-m²/s²
put these value in equation 1 we get
change in entropy = Q / ( K × T )
change in entropy = 155 / ( 1.38 × × 340 )
change in entropy = 3.3034 ×
so change in entropy is 3.3034 ×
