1
JEE Advanced 2014 Paper 2 Offline
+3
-1

Four charges Q1, Q2, Q3 and Q4 of same magnitude are fixed along the x axis at x = $$-$$2a, $$-$$a, +a and +2a, respectively. A positive charge q is placed on the positive y axis at a distance b > 0. Four options of the signs of these charges are given in List I. The direction of the forces on the charge q is given in List II. Match List I with List II and select the correct answer using the code given below the lists. List I List II
P. Q$$_1$$, Q$$_2$$, Q$$_3$$, Q$$_4$$ all positive 1. +x
Q. Q$$_1$$, Q$$_2$$ positive; Q$$_3$$, Q$$_4$$ negative 2. $$-$$x
R. Q$$_1$$, Q$$_4$$ positive; Q$$_2$$, Q$$_3$$ negative 3. +y
S. Q$$_1$$, Q$$_3$$ positive; Q$$_2$$, Q$$_4$$ negative 4. $$-$$y

A
P-3, Q-1, R-4, S-2
B
P-4, Q-2, R-3, S-1
C
P-3, Q-1, R-2, S-4
D
P-4, Q-2, R-1, S-3
2
JEE Advanced 2014 Paper 1 Offline
+4
-1
Let $${E_1}\left( r \right),{E_2}\left( r \right)$$ and $${E_3}\left( r \right)$$ be the respective electric field at a distance $$r$$ from a point charge $$Q,$$ an infinitely long wire with constant linear charge density $$\lambda ,$$ and an infinite plane with uniform surface charge density $$\sigma .$$ If $$E{}_1\left( {{r_0}} \right) = {E_2}\left( {{r_0}} \right) = {E_3}\left( {{r_0}} \right)$$ at a given distance $${r_0}.$$ then
A
$$Q = 4\sigma \pi r_0^2$$
B
$${r_0} = {\lambda \over {2\pi \sigma }}$$
C
$${E_1}\left( {{r_0}/2} \right) = 2{E_2}\left( {{r_0}/2} \right)$$
D
$${E_2}\left( {{r_0}/2} \right) = 4{E_3}\left( {{r_0}/2} \right)$$
3
JEE Advanced 2013 Paper 1 Offline
+4
-1
Two non-conducting solid spheres of radii $$R$$ and $$2R,$$ having uniform volume charge densities $${\rho _1}$$ and $${\rho _2}$$ respectively, touch each other. The net electric field at a distance $$2$$ $$R$$ from the center of the smaller sphere, along the line joining the centers of the spheres, is zero. The ratio $${{{\rho _1}} \over {{\rho _2}}}$$ can be
A
$$-4$$
B
$$- {{32} \over {25}}$$
C
$${{32} \over {25}}$$
D
$$4$$
4
IIT-JEE 2012 Paper 1 Offline
+4
-1
Consider a thin spherical shell of radius $$R$$ with center at the origin, carrying uniform positive surface charge density. The variation of the magnitude of the electric field $$\left| {\overrightarrow E \left( r \right)} \right|$$ and the electric potential $$V(r)$$ with the distance $$r$$ from the center, best represented by which graph?
A B C D Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
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