1
JEE Main 2021 (Online) 25th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Two billiard balls of equal mass 30g strike a rigid wall with same speed of 108 kmph (as shown) but at different angles. If the balls get reflected with the same speed then the ratio of the magnitude of impulses imparted to ball 'a' and ball 'b' by the wall along 'X' direction is :

JEE Main 2021 (Online) 25th July Morning Shift Physics - Center of Mass and Collision Question 41 English
A
1 : 1
B
$$\sqrt 2 $$ : 1
C
2 : 1
D
1 : $$\sqrt 2 $$
2
JEE Main 2021 (Online) 25th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
In the Young's double slit experiment, the distance between the slits varies in time as
d(t) = d0 + a0 sin$$\omega$$t; where d0, $$\omega$$ and a0 are constants. The difference between the largest fringe width and the smallest fringe width obtained over time is given as :
A
$${{2\lambda D({d_0})} \over {(d_0^2 - a_0^2)}}$$
B
$${{2\lambda D{a_0}} \over {(d_0^2 - a_0^2)}}$$
C
$${{\lambda D} \over {d_0^2}}{a_0}$$
D
$${{\lambda D} \over {{d_0} + {a_0}}}$$
3
JEE Main 2021 (Online) 25th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Two different metal bodies A and B of equal mass are heated at a uniform rate under similar conditions. The variation of temperature of the bodies is graphically represented as shown in the figure. The ratio of specific heat capacities is :

JEE Main 2021 (Online) 25th July Morning Shift Physics - Heat and Thermodynamics Question 181 English
A
$${8 \over 3}$$
B
$${3 \over 8}$$
C
$${3 \over 4}$$
D
$${4 \over 3}$$
4
JEE Main 2021 (Online) 25th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
A linearly polarized electromagnetic wave in vacuum is

$$E = 3.1\cos \left[ {(1.8)z - (5.4 \times {{10}^6})t} \right]\widehat iN/C$$

is incident normally on a perfectly reflecting wall at z = a. Choose the correct option
A
The wavelength is 5.4 m
B
The frequency of electromagnetic wave is 54 $$\times$$ 104 Hz.
C
The transmitted wave will be $$3.1\cos \left[ {(1.8)z - (5.4 \times {{10}^6})t} \right]\widehat iN/C$$
D
The reflected wave will be $$3.1\cos \left[ {(1.8)z + (5.4 \times {{10}^6})t} \right]\widehat iN/C$$
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