Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

NEET Physics Solved Question Paper 2011

Short Answer Type

41.

A shell of mass m is at rest initially. It explodes into three fragments having masses in the ratio 2 : 2 : 1. The fragments having equal masses fly off along mutually perpendicular direction with speed v. What will be the speed of the third (lighter) fragment ?

42.

A small spherical ball of mass m slides without friction from the top of a hemisphere of radius R. At what height will the ball lose contact with surface of the sphere ?

43.
Two identical cylindrical vessels, with their bases at the same level, each contain a liquidof density ρ. The height of liquid in one vessel in h₁ and that in the other is h₂. The area of either base is A. What is the work done by gravity in equalizing the levels when the vessels are interconnected ?

The figure can be shown diagrammatically as

Let us assume that the height = h

So, $h = (\frac{h_{1} + h_{2}}{2})$

Hence decrease in height in vessel of height h₁

$∆ h = h_{1} - (\frac{h_{1} + h_{2}}{2}) = (\frac{h_{1} - h_{2}}{2})$

Mass of liquid would be equal to

$m = (\frac{h_{1} - h_{2}}{2}) ρA$

Thus we can find the work done equal to

$W = mg ∆ h = (\frac{h_{1} - h_{2}}{2}) ρAg (\frac{h_{1} - h_{2}}{2}) = {(\frac{h_{1} - h_{2}}{2})}^{2} gρA$

44.

A battery of emf E and internal resistance r is connected across a pure resistive device (such as an electric heater) of resistance R. Prove that the power output of the device will be maximum if R = r.

45.

A radioactive isotope X with half life 1.5x 10⁹ yr decays into a stable nucleus Y. A rock sample contains both elements X and Y in ratio 1 : 15. Find the age of the rock.