The answer is:  [C]:  "protons and electrons" .
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Answer:
118.166 volt
Explanation:
We have given number of turns N =345 
Sides of the rectangular coils is 12 cm =0.12 m
So area A =0.12×0.12=0.0144 
Magnetic field B =0.45 T
Angular speed =505 rpm 
Speed in rad/sec 
The emf is given by  
 
For maximum emf sinwt =1
So 
 
        
             
        
        
        
Answer:
The number of crates is 84580.
Explanation:
mass, m = 30 kg
height, h = 0.9 mm  
Power, P = 0.5 hp = 0.5 x 746 W = 373 W
time, t = 1 minute = 60 s
Let the number of crates is n. 
Power is given by the rate of doing work. 

 
        
             
        
        
        
Answer:
B) Within an atom, an electron can have only particular energies.
Explanation:
As we know that electrons have energy but apart from electrons we know that protons and neutrons inside the nucleus of atom will also have energy in them.
rest all the statements are true as we have
A) Electrons orbit the nucleus rather like planets orbiting the Sun.
TRUE, because electrons can move in stationary orbit around the nucleus
C) Electrons can jump between energy levels in an atom only if they receive or give up an amount of energy equal to the difference in energy between the energy levels.
Difference amount of energy is lost or absorbed by the electron in form of photons
D) An electron has a negative electrical charge.
Charge of an electron is given as 
E) Electrons have very little mass compared to protons or neutrons
Mass of an electron is given as

mass of proton or neutron
