Given below are two statements:
Assertion (A): The charge on an isolated capacitor does not change by introducing a dielectric between the plates of the capacitor.
Reason (R): Charge on an isolated system is conserved.
 
1. Both (A) and (R) are True and (R) is the correct explanation of (A).
2. Both (A) and (R) are True but (R) is not the correct explanation of (A).
3. (A) is True but (R) is False.
4. (A) is False but (R) is True.

Subtopic:  Dielectrics in Capacitors |
 58%
Level 3: 35%-60%
Hints

A positively charged particle \(+q\) is projected with speed \(v\) toward a fixed charge \(+Q,\) and rebounds after reaching a minimum distance \(r.\) What will be the new closest distance of approach if its initial velocity is doubled to \(2v\text{?}\)

1. \(\dfrac{r}{4}\) 2. \(\dfrac{r}{2}\)
3. \(\dfrac{r}{16}\) 4. \(\dfrac{r}{8}\)
Subtopic:  Electric Potential Energy |
 73%
Level 2: 60%+
NEET - 2022
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Given below are two statements: 
Assertion (A): A metallic shield in the form of a hollow shell may be built to block an electric field.
Reason (R): In a hollow spherical shield, the electric field inside it is zero at every point.
 
1. Both (A) and (R) are True and (R) is the correct explanation of (A).
2. Both (A) and (R) are True but (R) is not the correct explanation of (A).
3. (A) is True but (R) is False.
4. (A) is False but (R) is True.
Subtopic:  Electrostatic Shielding |
 85%
Level 1: 80%+
Hints

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Choose the correct statements among the following:
A: Free electrons move always from a region of higher potential to a region of lower potential.
B: The capacitance of the capacitor does not depend upon the nature of the conducting material of the plates of the capacitor.
 
1. only A 2. only B
3. both A and B 4. neither A and B
Subtopic:  Capacitance |
Level 3: 35%-60%
Hints

The figure shows charge (\(q\)) versus voltage (\(V\)) graph for series and parallel combination of two given capacitors. The capacitances are:

       


1. \(50~\mu\text{F}\) and \(30~\mu\text{F}\)
2. \(20~\mu\text{F}\) and \(30~\mu\text{F}\) 
3. \(60~\mu\text{F}\) and \(40~\mu\text{F}\) 
4. \(40~\mu\text{F}\) and \(10~\mu\text{F}\)
Subtopic:  Capacitance |
 52%
Level 3: 35%-60%
Hints

Three capacitors each of capacity \(4\) µF are to be connected in such a way that the effective capacitance is \(6\) µF. This can be done by:

1.  connecting all of them in a series.
2. connecting them in parallel.
3. connecting two in series and one in parallel.
4. connecting two in parallel and one in series.

Subtopic:  Combination of Capacitors |
 90%
Level 1: 80%+
AIPMT - 2003
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A capacitor of capacity \(C_1\) is charged up to \(V\) volt and then connected to an uncharged capacitor \(C_2\). Then final P.D. across each will be:
1. \(\frac{C_{2} V}{C_{1} + C_{2}}\)
2. \(\frac{C_{1} V}{C_{1} + C_{2}}\)
3. \(\left(1 + \frac{C_{2}}{C_{1}}\right)\)
4. \(\left(1 - \frac{C_{2}}{C_{1}} \right) V\)

Subtopic:  Combination of Capacitors |
 81%
Level 1: 80%+
AIPMT - 2002
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The energy and capacity of a charged parallel plate capacitor are \(E\) and \(C\) respectively. If a dielectric slab of \(E_r=6\) is inserted in it, then the energy and capacity become:
(Assuming the charge on plates remains constant)
1. \(6 E,6 C\) 2. \( E,C\)
3. \(\frac{E}{6},6C\) 4. \(E,6C\)
Subtopic:  Energy stored in Capacitor |
 76%
Level 2: 60%+
AIPMT - 1999
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An electric dipole has the magnitude of its charges as \(q\) and its dipole moment is \(p\). It is placed in a uniform electric field \(E\). If its dipole moment is along the direction of the field, the force on it and its potential energy are respectively:
1. \(q\cdot E\) and \(p\cdot E \)
2. zero and minimum
3. \(q\cdot E\) and maximum
4. \(2q\cdot E\) and minimum 
Subtopic:  Energy of Dipole in an External Field |
 78%
Level 2: 60%+
AIPMT - 2004
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A bullet of mass \(2~\text {gm}\) has a charge of \(2~\mu\text{C}.\) Through what potential difference must it be accelerated, starting from rest, to acquire a speed of \(10~\text{m/s}?\)
1. \(50~\text {kV}\)
2. \(5~\text {V}\)
3. \(50~\text {V}\)
4. \(5~\text {kV}\)

Subtopic:  Electric Potential |
 78%
Level 2: 60%+
AIPMT - 2004
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