`L_(1)` is the length between two adjacent carbon atoms in a layer and `L_(2)` is the length in between two layers of graphite. The approximate ratio between `L_(1)` and `L_(2)` is

In graphite adjacent layers of carbon atoms are held together by

In the figure shown, there are two convex lenses L_(1) and L_(2) having focal. Lengths f_(1) and f_(2) respectively. The distance between L_(1) and L_(2) will be

Coefficient of coupling between two coils of self-inductances L_(1) and L_(2) is unity. It means

If L be the length of a bar magnet then separation between the two poles is naarly

(a) Explain with reason, how the power of a diverging lens changes when (i) it is kept in a medium of refractive index greater than that of the lens, (ii) incident red light is replaced by violet light. (b) Three lenses L_(1), L_(2), L_(3) each of focal length 30 cm are placed co-axially as shown in the figure. An object is held at 60 cm from the optic center of lens L_(1) . The final real image is formal at the focus of L_(3) . Calculate the separation between (i) (L_(1) and L_(2)) and " (ii) " (L_(2) and L_(3)) .

An isosceles triangles is formed with a thin rod of length l_(1) and coefficient of linear expansion alpha_(1) , as the base and two thin rods each of length l_(2) and coefficient of linear expansion alpha_(2) as the two sides. The distance between the apex and the midpoint of the base remain unchanged as the temperature is varied. the ratio of lengths (l_(1))/(l_(2)) is

An isosceles triangles is formed with a thin rod of length l_(1) and coefficient of linear expansion alpha_(1) , as the base and two thin rods each of length l_(2) and coefficient of linear expansion alpha_(2) as the two sides. The distance between the apex and the midpoint of the base remain unchanged as the temperature is varied. the ratio of lengths (l_(1))/(l_(2)) is

An isosceles triangles is formed with a thin rod of length l_(1) and coefficient of linear expansion alpha_(1) , as the base and two thin rods each of length l_(2) and coefficient of linear expansion alpha_(2) as the two sides. The distance between the apex and the midpoint of the base remain unchanged as the temperature is varied. the ratio of lengths (l_(1))/(l_(2)) is

Consider the lines L_(1) -=3x-4y+2=0 " and " L_(2)-=3y-4x-5=0. Now, choose the correct statement(s). (a)The line x+y=0 bisects the acute angle between L_(1) "and " L_(2) containing the origin. (b)The line x-y+1=0 bisects the obtuse angle between L_(1) " and " L_(2) not containing the origin. (c)The line x+y+3=0 bisects the obtuse angle between L_(1) " and " L_(2) containing the origin. (d)The line x-y+1=0 bisects the acute angle between L_(1) " and " L_(2) not containing the origin.

You are given three lenses L_(1),L_(2) and L_(3) each of focal length 10 cm. An object is kept at 15 cm in front of L_(1), as shown. The final real image is formed at the focus 'T' of L_(3). Find the separations between L_(1),L_(2) and L_(3).