Answer:
Explanation:
  For entry of light into tube of unknown refractive index 
sin ( 90 - 25 ) / sinr = μ , μ is the refractive index of the tube , r is angle of refraction in the medium of tube 
r = 90 - C where C is critical angle between μ and body medium in which tube will be inserted. 
sin ( 90 - 25 ) / sin( 90 - C)  = μ
sin65 / cos C = μ
sinC = 1.33 / μ  , where 1.33 is the refractive index of body liquid. 
From these equations
sin65 / cos C = 1.33 / sinC 
TanC = 1.33 / sin65
TanC = 1.33 / .9063
TanC = 1.4675
C= 56°
sinC = 1.33 / μ
 μ = 1.33 / sinC
= 1.33 / sin56
= 1.33 / .829
μ = 1.6   Ans 
 
        
             
        
        
        
Answer:

The Magnitude of electric field is in the upward direction as shown directly towards the charge  .
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Explanation:
Given:
- side of a square,  
- charge on one corner of the square,  
- charge on the remaining 3 corners of the square, 
<u>Distance of the center from each corners</u>


∴Distance of center from corners, 
Now, electric field due to charges is given as:

<u>For charge  we have the field lines emerging out of the charge since it is positively charged:</u>
 we have the field lines emerging out of the charge since it is positively charged:</u>

<u>Force by each of the charges at the remaining corners:</u>

<u> Now, net electric field in the vertical direction:</u>


<u>Now, net electric field in the horizontal direction:</u>
 
 
So the Magnitude of electric field is in the upward direction as shown directly towards the charge  .
.
 
        
             
        
        
        
The use of drugs to treat disease is called medication
        
                    
             
        
        
        
Answer:
A sound wave is called a longitudinal wave because compressions and rarefactions in the air produce it. The air particles vibrate parallel to the direction of propagation.