First focal point.
Answer:-
The first focal point is a point on the principal axis of the lens such that a beam of light passing through it is rendered parallel to the principal axis after refraction through the lens.
angle of contact.
It is defined as the angle between the tangent to the liquid surface at the point of contact and solid surface inside the liquid is called as angle of contact The value of angle of contact depends upon (i) Nature of solid and liquid in contact (ii) Cleanliness of the surface in contact (iii) Medium above the free surface of liquid
Comments
Post a Comment