1
JEE Main 2020 (Online) 6th September Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Given the masses of various atomic particles
mp = 1.0072 u, mn = 1.0087 u, me = 0.000548 u,
$${m_{\overline v }}$$ = 0, md = 2.0141 u, where p $$ \equiv $$ proton, n $$ \equiv $$ neutron,
e $$ \equiv $$ electron, $$\overline v $$ $$ \equiv $$ antineutrino and d $$ \equiv $$ deuteron. Which of the following process is allowed by momentum and energy conservation?
A
n + n $$ \to $$ deuterium atom
(electron bound to the nucleus)
B
n + p $$ \to $$ d + $$\gamma $$
C
p $$ \to $$ n + e+ + $$\overline v $$
D
e+ + e- $$ \to $$ $$\gamma $$
2
JEE Main 2020 (Online) 6th September Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
A particle moving in the xy plane experiences a velocity dependent force
$$\overrightarrow F = k\left( {{v_y}\widehat i + {v_x}\widehat j} \right)$$ , where vx and vy are the
x and y components of its velocity $$\overrightarrow v $$ . If $$\overrightarrow a $$ is the
acceleration of the particle, then
which of the following statements is true for the particle?
A
kinetic energy of particle is constant in time
B
quantity $$\overrightarrow v \times \overrightarrow a $$ is constant in time
C
quantity $$\overrightarrow v .\overrightarrow a $$ is constant in time
D
$$\overrightarrow F $$ arises due to a magnetic field
3
JEE Main 2020 (Online) 6th September Evening Slot
Numerical
+4
-0
Change Language
A Young's double-slit experiment is performed using monochromatic light of wavelength $$\lambda $$. The intensity of light at a point on the screen, where the path difference is $$\lambda $$, is K units. The intensity of light at a point where the path difference is $${\lambda \over 6}$$ is given by $${{nK} \over {12}}$$, where n is an integer. The value of n is __________.
Your input ____
4
JEE Main 2020 (Online) 6th September Evening Slot
Numerical
+4
-0
Change Language
The centre of mass of solid hemisphere of radius 8 cm is x from the centre of the flat surface. Then value of x is __________.
Your input ____
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