Answer:
15.32°
Explanation:
We have given the wavelength 
Diffraction grating is 1460 lines per cm
So 
(as 1 m=100 cm )
For maximum diffraction
here m is order of diffraction
So 
Answer:
Melt.
Explanation:
When rocks melt, they do so slowly and gradually because most rocks are made of several minerals, which all have different melting points; moreover, the physical and chemical relationships controlling the melting are complex. As a rock melts, for example, its volume changes. When enough rock is melted, the small globules of melt link up and soften the rock.
Under normal conditions, mantle rock like peridotite shouldn't melt in the Earth's upper mantle. However, by adding water you can lower the melting point of the rock. Alternatively, by decompressing the rock, you can bring it to a pressure where the melting point is lower. In both cases, basalt magma will form and considering it is hotter and less dense than the surrounding rock, it will percolate towards the surface and some of that erupts.
Renewable energy
<u>Advantages :-</u>
1. Easily regenerate
2. Boost economic growth
3. Easily available
4. Support environment
5. Low maintenance cost
<u>Disadvantages :-</u>
1. Weather dependency
2. High installation cost
3. Noise caused by wind energy
4. Fluctuation problem (solar)
5. Intermittency issue (wind)
Non-renewable energy
<u>Advantages :-</u>
1. Concentrated energy source
2. Reliable energy source
3. Can be built anywhere
4. No radioactive waste
<u>Disadvantages :-</u>
1. Produces greenhouse gases
2. Contributes to global warming
3. Produces acid rain
4. Harmful to environment when they are burnt
<em>I hope this helps.....</em>
Answer : 6.022• 10^23 atoms of potassium
