<span>The equation that relates Wavelength & frequency of electromagnetic waves is :
Velocity (c) = Wavelength (λ) * frequency (f) ------ (1)
Electromagnetic wave velocity (c) = Speed of Light = 3 * 10^8 m/s
From (1),
Wavelength , λ = c / f
λ= (3*10^8)/(980*10^3)
λ = 306.12 m
Minimum height of the antenna for effective transmission = λ * 0.5 = 306.12*0.5
Answer : 153 m (rounded off)</span>
Answer:
Explanation:
Distance travelled by sound in going to target( insect ) and returning back = 2d ,d is distance of target .
time t = .06 s
speed = distance / time
344.9 = 2d / .06
d = 10.35 m
Answer:
0.5 s
Explanation:
From the question given above, the following data were obtained:
Number of circle (n) = 2
Time (t) = 1 s
Period =?
Period of a wave is simply defined as the time taken to make one complete oscillation. Mathematically, it can be expressed as:
T = t / n
Whereb
T => is the period
t => is the space time
n => is the number of circle or oscillation.
With the above formula, we can obtain the period of the wave as follow:
Number of circle (n) = 2
Time (t) = 1 s
Period =?
T = t / n
T = 1 / 2
T = 0.5 s
Thus, the period of the wave is 0.5 s
Explanation:
spectral lines or signatures of elements depend on temperature, the temperature of the sun is about 5800 K.
at this temperature most calcium atoms are excited to higher energy states than hydrogen atoms and this means that calcium atoms are gonna have more signatures than the atoms of hydrogen.
the statement that the sun shows weak hyrogen lines and strong calcium line is wrong because at the sun's temperature most of the hydrogen atoms are in lower energy states while calcium atoms are in higher energy states hence calcium has more or ''strong'' lines than hydrogen.
Answer:
except ii and iii
Explanation:
The angle of reflection is the angle to the normal the white rays strikes the water surface and it is the incidence angle. Since the white light is moving from less dense medium to a denser medium or a medium with a higher refractive index; the angle of refraction will be less than 30 degrees. Total internal reflection cannot occur because the white light is traveling from a less dense medium to a denser medium.
