Javascript is required
1
JEE Main 2021 (Online) 18th March Evening Shift
+4
-1
If the angular velocity of earth's spin is increased such that the bodies at the equator start floating, the duration of the day would be approximately : [Take g = 10 ms$$-$$2, the radius of earth, R = 6400 $$\times$$ 103 m, Take $$\pi$$ = 3.14]
A
84 minutes
B
1200 minutes
C
60 minutes
D
does not change
2
JEE Main 2021 (Online) 18th March Evening Shift
+4
-1
The angular momentum of a planet of mass M moving around the sun in an elliptical orbit is $${\overrightarrow L }$$. The magnitude of the areal velocity of the planet is :
A
$${{2L} \over M}$$
B
$${{L} \over 2M}$$
C
$${{L} \over M}$$
D
$${{4L} \over M}$$
3
JEE Main 2021 (Online) 18th March Morning Shift
+4
-1
Match List - I with List - II.

List - I

(a) 10 km height over earth's surface

(b) 70 km height over earth's surface

(c) 180 km height over earth's surface

(d) 270 km height over earth's surface

List - II

(i) Thermosphere

(ii) Mesosphere

(iii) Stratosphere

(iv) Troposphere
A
(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
B
(a)-(i), (b)-(iv), (c)-(iii), (d)-(ii)
C
(a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)
D
(a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
4
JEE Main 2021 (Online) 18th March Morning Shift