1
AIPMT 2012 Prelims
+4
-1
ABC is an equilateral triangle with O as its centre. $${\overrightarrow F _1},{\overrightarrow F _2}$$ and $${\overrightarrow F _3}$$ represent three forces acting along the sides AB, BC and AC respectively. If the total torque about O is zero then magnitude of $${\overrightarrow F _3}$$ is

A
F1 + F2
B
F1 $$-$$ F2
C
$${{{F_1} + {F_2}} \over 2}$$
D
2(F1 + F2)
2
AIPMT 2011 Mains
+4
-1
A small mass attached to a string rotates on a frictionless table top as shown. If the tension in the string is increased by pulling the string causing the radius of the circular motion to decrease by a factor of 2, the kinetic energy of the mass will

A
decrease by a factor of 2
B
remain constant
C
increase by a factor of 2
D
increase by a factor of 4
3
AIPMT 2011 Prelims
+4
-1
The moment of inertia of a thin uniform rod of mass M and length L about an axis passing through its midpoint and perpendicular to its length is $$I$$0. Its moment of inertia about an axis passing through one of its ends and perpendicular to its length is
A
$${I_0} + M{L^2}/2$$
B
$${I_0} + M{L^2}/4$$
C
$${I_0} + 2M{L^2}$$
D
$${I_0} + M{L^2}$$
4
AIPMT 2011 Prelims
+4
-1
The instantaneous angular position of a point on a rotating wheel is given by the equation $$\theta \left( t \right) = 2{t^3} - 6{t^2}$$

The torque on the wheel becomes zero at
A
t = 1 s
B
t = 0.5 s
C
t = 0.25 s
D
t = 2 s
EXAM MAP
Medical
NEETAIIMS