The Bohr's proposal for the angular momentum of an electron in Bohr's model of the hydrogen atom is:
L=(n*h)/(2π), where n is the number of the energy level and h is the Planck's constant. This equation shows us the quantization of angular momentum of the electron. So the correct answer is the second one: Planck's constant.
Answer:
The block's mass should be 
Explanation:
Given:
Cart with mass 
From the conservation of energy before mass is added,

Where
amplitude of spring mass system,
spring constant

Now new mass
is added to the system,


Here, given in question frequency is reduced to half so we can write,

Where
frequency of system before mass is added,
frequency of system after mass is added.




Therefore, the block's mass should be 
Answer:
Voltage in primary coil is 3.91 V
Explanation:
For transformer we know that the working principle is given as

here we know that
![V_1 [tex] = voltage in primary coil[tex]V_2 = 25 V](https://tex.z-dn.net/?f=V_1%20%5Btex%5D%20%3D%20voltage%20in%20primary%20coil%3C%2Fp%3E%3Cp%3E%5Btex%5DV_2%20%3D%2025%20V)


Now we have


Fetal because you are still in the womb and not fully developed
Positive. The 1st object loses electrons and will thus have an imbalance of charge with loss of electrons.