ক্রাউন গ্লাস `(mu=(3)/(2))` থেকে তৈরি একটি পাতলা উত্তল লেন্সের ফোকাল লেন্থ f আছে। কখন

A thin convex lens made from crown glass (mu=(3)/(2)) has focal length f. When it is measured in two different liquids having refractive indices (4)/(3) and (5)/(3) , it has the focal lengths f_1 and f_2 respectively . The correct relation between the focal lengths is ,

Assertion: A body of weight 10N (W) is at rest on an inclined plane (mu=sqrt(3)/(2)) making an angle of 30^(@) with the horizontal. The force of friction acting on it is 5N Reason: In above situation, the limiting force of friction is given by f_("limitting")=mu W cos theta=7.5N .

Plot a graph showing the variation of coulomb force (F) versus ((1)/(r^(2))) , where r is the distance between the two charges of each pair of charges: (1mu C,2mu C) and (2muC-3muC) . Interpet the graphs obtained.

Assertion : When a convex lens (mu_(g) = 3//2) of focal length f is dipped in water, its focal length become (4)/(3)f Reason : The focal length of convex lens in water becomes 4f.

A convex lens made of glass ( mu_(g) = 3/2) has focal length f in air. The image of an object placed . infront of it is inverted real and magnified. Now the whole arrangement is immersed in water ( mu_(w) = 4/3) without changing the distance between object and lens. Then

A right angled prism of refractive index mu_(1) is placed in a rectangular block of refractive index mu_(2) , which is surrounded by a medium of refractive index mu_(3) ,as shown in the figure . A ray of light 'e' enters the rectangular block at normal incidence . depending upon the relationship between mu_(1) , mu_(2) "and" mu_(3) , it takes one of the four possible paths 'ef' , 'eg' , 'eh' or 'ef' Match the paths in List I with conditions of refractive indices in List II and select the correct answer using the codes given below the lists: {:("List" I , "List" II) , ( P. e rarr f , 1. mu_(1)gt sqrt(2mu_(2))) , ( Q. e rarr g , 2. mu_(2) gt mu_(1) "and" mu_(2) gt mu_(3)), ( R. e rarr f , 3. mu_(1) = mu_(2)), ( S. e rarr f , 4. mu_(2) lt mu_(1) lt sqrt(2mu_(2)) "and" mu_(2) gt mu_(3)):} Codes : {:( P , Q , R , S) , ((A) 2 , 3 , 1 , 4), ((B) 1 , 2 , 4 , 3) , ((C) 4 , 1 , 2 , 3) , ((D) 2, 3 , 4 , 1):}

Two identical glass (mu_(g)=3//2) equiconvex lenses of focal length f are kept in contact. The space between the two lenses is filled with water (mu_(w)=4//3) . The focal length of the combination is