JEE Main 2020 Question Paper (08-Jan-2020) (Shift 2)

Question 1

A uniform sphere of mass $500\ \mathrm{g}$ rolls without slipping on a plane horizontal surface with its centre moving at a speed of $5.00\ \mathrm{cm\ s^{-1}}$. Its kinetic energy is:

Accepted Answer

$8.75 	imes 10^{-4} 	ext{\hspace{0.17em}} \mathrm{J}$

Answer

$8.75 	imes 10^{-3} 	ext{ J}$

Answer

$6.25 	imes 10^{-4} 	ext{\hspace{0.17em}} \mathrm{J}$

Answer

$1.13 	imes 10^{-3} 	ext{\hspace{0.17em}} \mathrm{J}$

Question 2

An object is gradually moving away from the focal point of a concave mirror along the axis of the mirror. The graphical representation of the magnitude of linear magnification $ \left(m\right) $ versus distance of the object from the mirror $ \left(x\right) $ is correctly given by
(Graphs are drawn schematically and are not to scale)

Accepted Answer

""

Answer

Answer

Answer

Question 3

A transverse wave travels on a taut steel wire with a velocity of $v$ when the tension in it is $2.06 	imes 10^{4}\,\mathrm{N}$. When the tension is changed to $T$, the velocity changes to $\frac{v}{2}$. The value of $T$ is close to:

Accepted Answer

$5.15 	imes 10^{3} 	ext{\hspace{0.17em}} \mathrm{N}$

Answer

$2.50 	imes 10^{4} \mathrm{N}$

Answer

$30.5 	imes 10^{4} 	ext{ N}$

Answer

$10.2 	imes 10^{2} 	ext{ N}$

Question 4

Consider a mixture of $ n $ moles of helium gas and $ 2n $ moles of oxygen gas (molecules taken to be rigid) as an ideal gas. Its $\frac{C_{P}}{C_{V}}$ value will be:

Accepted Answer

$\frac{19}{13}$

Answer

$\frac{67}{45}$

Answer

$\frac{40}{27}$

Answer

$\frac{23}{15}$

Question 5

As shown in the figure, when a spherical cavity (centred at $ O $) of radius $ 1 $ is cut out of a uniform sphere of radius $ R $ (centred at $ C $), the centre of mass of the remaining (shaded) part of the sphere is at $ G $, i.e., on the surface of the cavity. $ R $ can be determined by the equation:

Accepted Answer

$\left(R^{2} + R + 1\right)\left(2 - R\right) = 1$

Answer

$ \left(R^{2} - R - 1\right)(2 - R) = 1 $

Answer

$\left(R^{2} - R + 1\right)\left(2 - R\right) = 1$

Answer

$\left(R^{2} + R - 1\right)\left(2 - R\right) = 1$