Answer:
For destructive interference phase difference is
  where n∈ Whole numbers
 where n∈ Whole numbers
Explanation:
For sinusoidal wave the interference affects the resultant intensity of the waves.
In the given example we have two waves interfering at a phase difference of  would lead to a constructive interference giving maximum amplitude at at the RMS value of the amplitude in resultant.
 would lead to a constructive interference giving maximum amplitude at at the RMS value of the amplitude in resultant.
Also the effect is same as having a phase difference of   because after each 2π the waves repeat itself.
 because after each 2π the waves repeat itself.
<em>In case of destructive interference the waves will be out of phase i.e. the amplitude vectors will be equally opposite in the direction at the same place on the same time as shown in figure.</em>
They have a phase difference of  or which is same as
 or which is same as 
Generalizing to:
a phase difference of  where n∈ {W}
 where n∈ {W} 
{W}= set of whole numbers.
 
        
             
        
        
        
Answer:
The lenses with different focal length are four.
Explanation:
Given that,
Radius of curvature R₁= 4
Radius of curvature R₂ = 8
We know ,
Refractive index of glass = 1.6
When, R₁= 4, R₂ = 8
We need to calculate the focal length of the lens
Using formula of focal length

Put the value into the formula



When , R₁= -4, R₂ = 8
Put the value into the formula



When , R₁= 4, R₂ = -8
Put the value into the formula



When , R₁= -4, R₂ = -8
Put the value into the formula



Hence, The lenses with different focal length are four.
 
        
             
        
        
        
Answer: A if thats not right its C
Explanation:
 
        
                    
             
        
        
        
1.A
2. C
3. Not Sure
4. Not Sure
5. Biometrics can help to identify
who's at risk for injuries and when
they're able to safely return, and
they can gauge athlete readiness to
determine when they'll be
performing at an optimal level.
        
                    
             
        
        
        
Answer:
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Explanation:
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