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.
The correct answer to the question is: A) miles/hour and B) metre/ second.
EXPLANATION:
Before answering this question, first we have to understand speed.
The speed of a body is defined as the rate of distance travelled or the distance travelled by a body per unit time.
Hence, it is a derived quantity which is obtained from distance and time.
The unit of distance can be metre, miles, and the unit of time can be second, minutes or hour.
As speed is the distance covered per unit time, the perfect units will be miles/hour and metre/second.
Hence, the correct options are first and second.
Answer:
Range of wavelength will be 
to 
Explanation:
We have given range of frequency is 400-560 Hz
Speed of the light 
We have to find the range of the wavelength of signal transmitted
Ween know that velocity is given by 
, here 
is wavelength and f is frequency
So for 400 Hz frequency wavelength will be 
And wavelength for frequency 560 Hz 
So range of wavelength will be to
The main difference between<span> the two is that Enlightenment rationalism dwells in abstract inwardness. and it is only through this echo that German Christianity is ...</span>
D) Both A and B.
Francisco Redi must use 1)a covered, unrefrigerated meat and 2) an uncovered, refrigerated meat to experiment and test his hypothesis that maggots came from flies rather than from meat.
