Physics
Assertion (A) : Camels can walk easily in deserts without their feet sinking in sand.
Reason (R) : Camels have large broad feet with a wide base, thus increasing the pressure exerted on sand.
- Both A and R are true and R is the correct explanation of A
- Both A and R are true and R is not the correct explanation of A
- Assertion is true but reason is false
- Assertion is false but reason is true
Answer
Assertion is true but reason is false
Explanation
A camel’s broad feet spread its weight over a larger area, so the pressure it exerts on the sand is lower; this prevents its feet from sinking. Hence the Assertion is correct. The Reason, however, is incorrect because the feet decrease, not increase, the pressure on the sand.
Related Questions
Assertion (A) : A force when applied on a body changes its mass.
Reason (R) : Force is the cause which changes the size or shape of the body.
- Both A and R are true and R is the correct explanation of A
- Both A and R are true and R is not the correct explanation of A
- Assertion is true but reason is false
- Assertion is false but reason is true
Assertion (A) : In heavy container trucks, more number of tyres are used to reduce the pressure on the ground.
Reason (R) : Larger the surface area, less is the pressure for the same thrust.
- Both A and R are true and R is the correct explanation of A
- Both A and R are true and R is not the correct explanation of A
- Assertion is true but reason is false
- Assertion is false but reason is true
Fill in the blanks:
(a) 1 kgf = …………… N (nearly).
(b) Moment of force = …………… x distance of force from the point of turning.
(c) In a door, handle is provided …………… from the hinges.
(d) The unit of thrust is …………… .
(e) Thrust is the …………… force acting on a surface.
(f) Pressure is the thrust acting on a surface of …………… area.
(g) The unit of pressure is …………… .
(h) Pressure is reduced if …………… increases.
(i) Pressure in a liquid …………… with the depth.
(j) The atmospheric pressure on earth surface is nearly …………… .
Write true or false for each statement:
(a) The S.I. unit of force is kgf.
(b) A force always produces both the linear and turning motions.
(c) Moment of force = force x perpendicular distance of force from the pivoted point.
(d) Less force is needed when applied at a farther distance from the pivoted point.
(e) For a given thrust, pressure is more on a surface of large area.
(f) The pressure on a surface increases with an increase in the thrust on the surface.
(g) A man exerts same pressure on the ground whether he is standing or he is lying.
(h) It is easier to hammer a blunt nail into a piece of wood than a sharply pointed nail.
(i) The S.I. unit of pressure is pascal.
(j) Water in a lake exerts pressure only at its bottom.
(k) A liquid exerts pressure in all directions.
(l) Gases exert pressure in all directions.
(m) The atmospheric pressure is nearly 105 Pa.
(n) Higher we go, greater is the air pressure.