1
JEE Advanced 2018 Paper 2 Offline
+3
-0.75
The electric field $$E$$ is measured at a point $$P(0,0,d)$$ generated due to various charge distributions and the dependence of $$E$$ on $$d$$ is found to be different for different charge distributions. List-$${\rm I}$$ contains different relations between $$E$$ and $$d$$. List-$${\rm II}$$ describes different electric charge distributions, along with their locations. Match the functions in List-$${\rm I}$$ with the related charge distributions in List-$${\rm II}$$.

LIST - I LIST - II
P. $$E$$ is independent of $$d$$ 1. A point charge Q at the origin
Q. $$E\, \propto \,1/d$$ 2. A small dipole with point charges
$$Q$$ at $$\left( {0,0,l} \right)$$ and $$-Q$$ at
$$\left( {0,0, - l} \right).$$ Take $$2l < < d$$
R. $$E\, \propto \,1/{d^2}$$ 3. An infinite line charge coincident
with the x-axis, with uniform linear charge density $$\lambda$$
S. $$E\, \propto \,1/{d^3}$$ 4. Two infinite wires carrying
uniform linear charge density
parallel to the $$x$$-axis. The one
along $$\left( {y = 0,z = l} \right)$$ has
a charge density $$+ \lambda$$ and the one
along $$\left( {y = 0,z = - l} \right)$$ has a
charge density Take
5. Infinite plane charge coincident
with the $$xy$$-plane with uniform surface charge density
A
$$P \to 5;Q \to 3,4;R \to 1;S \to 2$$
B
$$P \to 5;Q \to 3;R \to 1,4;S \to 2$$
C
$$P \to 4;Q \to 3;R \to 1,2;S \to 4$$
D
$$P \to 4;Q \to 2,3;R \to 1;S \to 5$$
2
JEE Advanced 2016 Paper 2 Offline
+3
-0
Consider an evacuated cylindrical chamber of height h having rigid conducting plates at the ends and an insulating curved surface as shown in the figure. A number of spherical balls made of a light weight and soft material and coated with a conducting material are placed on the bottom plate. The balls have a radius r << h. Now, a high voltage source (HV) connected across the conducting plates such that the bottom plate is at +V0 and the top plate at $$-$$V0. Due to their conducting surface, the balls will get charge, will become equipotential with the plate and are repelled by it. The balls will eventually collide with the top plate, where the coefficient of restitution can be taken to be zero due to the soft nature of the material of the balls. The electric field in the chamber can be considered to be that of a parallel plate capacitor. Assume that there are no collisions between the balls and the interaction between them is negligible. (Ignore gravity)

Which one of the following statement is correct?
A
The balls will execute simple harmonic motion between the two plates
B
The balls will bounce back to the bottom plate carrying the same charge they went up with
C
The balls will stick to the top plate and remain there
D
The balls will bounce back to the bottom plate carrying the opposite charge they went up with
3
JEE Advanced 2016 Paper 2 Offline
+3
-0
Consider an evacuated cylindrical chamber of height h having rigid conducting plates at the ends and an insulating curved surface as shown in the figure. A number of spherical balls made of a light weight and soft material and coated with a conducting material are placed on the bottom plate. The balls have a radius r << h. Now, a high voltage source (HV) connected across the conducting plates such that the bottom plate is at +V0 and the top plate at $$-$$V0. Due to their conducting surface, the balls will get charge, will become equipotential with the plate and are repelled by it. The balls will eventually collide with the top plate, where the coefficient of restitution can be taken to be zero due to the soft nature of the material of the balls. The electric field in the chamber can be considered to be that of a parallel plate capacitor. Assume that there are no collisions between the balls and the interaction between them is negligible. (Ignore gravity)

The average current in the steady state registered by the ammeter in the circuit will be
A
proportional to $$V_0^2$$
B
proportional to the potential $${V_0}$$
C
zero
D
proportions to $$V_0^{1/2}$$
4
JEE Advanced 2014 Paper 2 Offline
+3
-1
Charges $$Q,$$ $$2Q$$ and $$4Q$$ are uniformly distributed in three dielectric solid spheres $$1,2$$ and $$3$$ of radii $$R/2,R$$ and $$2R$$ respectively, as shown in figure. If magnitude of the electric fields at point $$P$$ at a distance $$R$$ from the center of sphere $$1,2$$ and $$3$$ are $${E_1}$$, $${E_2}$$ and $${E_3}$$ respectively, then

A
$${E_1} > {E_2} > {E_3}$$
B
$${E_3} > {E_1} > {E_2}$$
C
$${E_2} > {E_1} > {E_3}$$
D
$${E_3} > {E_2} > {E_1}$$
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