1
JEE Main 2016 (Online) 10th April Morning Slot
+4
-1
An astronaut of mass m is working on a satellite orbiting the earth at a distance h from the earth’s surface. The radius of the earth is R, while its mass is M. The gravitational pull FG on the astronaut is :
A
Zero since astronaut feels weightless
B
0 < FG < $${{GMm} \over {{R^2}}}$$
C
$${{GMm} \over {{{\left( {R + h} \right)}^2}}}$$ < FG < $${{GMm} \over {{R^2}}}$$
D
FG = $${{GMm} \over {{{\left( {R + h} \right)}^2}}}$$
2
JEE Main 2016 (Online) 9th April Morning Slot
+4
-1
Figure shows elliptical path abcd of a planet around the sun S such that the area of triangle csa is $${1 \over 4}$$ the area of the ellipse. (See figure) With db as the semimajor axis, and ca as the semiminor axis. If t1 is the time taken for planet to go over path abc and t2 for path taken over cda then :

A
t1 = t2
B
t1 = 2t2
C
t1 = 3t2
D
t1 = 4t2
3
JEE Main 2016 (Offline)
+4
-1
A satellite is revolving in a circular orbit at a height $$'h'$$ from the earth's surface (radius of earth $$R;h < < R$$). The minimum increase in its orbital velocity required, so that the satellite could escape from the earth's gravitational field, is close to : (Neglect the effect of atmosphere.)
A
$$\sqrt{2 g R}$$
B
$$\sqrt{g R}$$
C
$$\sqrt{g R / 2}$$
D
$$\sqrt{g R}(\sqrt{2}-1)$$
4
JEE Main 2015 (Offline)
+4
-1
From a solid sphere of mass $$M$$ and radius $$R,$$ a spherical portion of radius $$R/2$$ is removed, as shown in the figure. Taking gravitational potential $$V=0$$ at $$r = \infty ,$$ the potential at the center of the cavity thus formed is:
($$G=gravitational$$ $$constant$$)
A
$${{ - 2GM} \over {3R}}$$
B
$${{ - 2GM} \over R}$$
C
$${{ - GM} \over {2R}}$$
D
$${{ - GM} \over R}$$
JEE Main Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
EXAM MAP
Joint Entrance Examination