The effective area of a rough body is always greater than its geometrical area . On blackening the bottom of rough bodies ,their absorptance increases . True/False.

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if asssertion is true, but reason if false, (D) if both assertion and reason are false Assertion : The e.m.f. of a cell is always greater than the terminal potential difference between its two pole. Reason: There is always some potential drop across the internal resistance of the cell.

true or false mortality increases the population of the species in an area.

Which of the following statements are true/false. Proper fraction is always greater than 1

True or False statements: For any function f a local maximum value is always greater than a local minimum value.

When a body slides down from rest along a smooth inclined plane making anangle of 45^@ with the horizontal, it takes time T. when the same body slides down from rest along a rough inclined plane making the same angle and through the same distance, it is seen to take time pT, where p is some number greater than 1. Calculate the co-efficient of friction between the body and the rough plane.

The resistivity of a substance depends on its length and area of cross section. Is the statement true or false.

True/False: If each side of a triangle is doubled, then the percentage increase in its area is 200%

State whether the given statements are true or false. Sum of the lengths of a polygon is called its area.