21. Assertion : paper pins are made to have pointed end. Reason : Because pointed pins have very smalll area due to which even for small applied force it exert large pressure on the surface.

(a)       If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b)       If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c)        If assertion is true but reason is false.

(d)       If the assertion and reason both are false.

(e)       If assertion is false but reason is true.

Explanation-(a) Smaller the area, larger the pressure exerted by a force

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