A capacitor of \(2~\mu\text{F}\) is charged as shown in the figure. When the switch \({S}\) is turned to position \(2,\) the percentage of its stored energy dissipated is:

       
1. \(20\%\)
2. \(75\%\)
3. \(80\%\)
4. \(0\%\)

Subtopic:  Energy stored in Capacitor |
 71%
Level 2: 60%+
NEET - 2016
Hints
Links

If potential \([\text{in volts}]\) in a region is expressed as \(V[x,y,z] = 6xy-y+2yz,\) the electric field \([\text{in N/C}]\) at point \((1, 1, 0)\) is:

1. \(- \left(3 \hat{i} + 5 \hat{j} + 3 \hat{k}\right)\) 2. \(- \left(6 \hat{i} + 5 \hat{j} + 2 \hat{k}\right)\)
3. \(- \left(2 \hat{i} + 3 \hat{j} + \hat{k}\right)\) 4. \(- \left(6 \hat{i} + 9 \hat{j} + \hat{k}\right)\)
Subtopic:  Relation between Field & Potential |
 85%
Level 1: 80%+
NEET - 2015
Hints
Links

A parallel plate air capacitor has capacitance \(C,\) the distance of separation between plates is \(d\) and potential difference \(V\) is applied between the plates. The force of attraction between the plates of the parallel plate air capacitor is:

1. \(\frac{C^2V^2}{2d}\) 2. \(\frac{CV^2}{2d}\)
3. \(\frac{CV^2}{d}\) 4. \(\frac{C^2V^2}{2d^2}\)
Subtopic:  Capacitance |
 71%
Level 2: 60%+
NEET - 2015
Hints
Links

advertisementadvertisement

Two thin dielectric slabs of dielectric constants \(K_1\) and \(K_2\) \((K_1<K_2)\) are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field \('E'\) between the plates with distance \('d'\) as measured from the plate \(P\) is correctly shown by: 

1. 2.
3. 4.
Subtopic:  Dielectrics in Capacitors |
 79%
Level 2: 60%+
AIPMT - 2014
Hints
Links

In a region, the potential is represented by \(V=(x,y,z)=6x-8xy-8y+6yz,\) where \(V\) is in volts and \(x,y,z\) are in meters. The electric force experienced by a charge of \(2\) coulomb situated at a point \((1,1,1)\) is:
1. \(6\sqrt{5}~\text{N}\) 2. \(30~\text{N}\)
3. \(24~\text{N}\) 4. \(4\sqrt{35}~\text{N}\)
Subtopic:  Relation between Field & Potential |
 73%
Level 2: 60%+
AIPMT - 2014
Hints
Links

\(A\), \(B\) and \(C\) are three points in a uniform electric field. The electric potential is: 

     
1. maximum at \(B\)
2. maximum at \(C\)
3. same at all the three points \(A, B\) and \(C\)
4. maximum at \(A\)
Subtopic:  Relation between Field & Potential |
 86%
Level 1: 80%+
AIPMT - 2013
Hints
Links

advertisementadvertisement

An electric dipole of moment \(p\) is placed in an electric field of intensity \(E.\) The dipole acquires a position such that the axis of the dipole makes an angle \(\theta\) with the direction of the field. Assuming that the potential energy of the dipole to be zero when \(\theta = 90^{\circ}\), the torque and the potential energy of the dipole will respectively be:
1. \(pE\text{sin}\theta, ~-pE\text{cos}\theta\)
2. \(pE\text{sin}\theta, ~-2pE\text{cos}\theta\)
3. \(pE\text{sin}\theta, ~2pE\text{cos}\theta\)
4. \(pE\text{cos}\theta, ~-pE\text{sin}\theta\)

Subtopic:  Energy of Dipole in an External Field |
 84%
Level 1: 80%+
AIPMT - 2012
Hints
Links

Three capacitors each of capacitance \(C\) and of breakdown voltage \(V\) are joined in series. The capacitance and breakdown voltage of the combination will be:
1. C3, V3

2. 3C, V3

3. C3, 3V

4. \(3C,~3V\)

Subtopic:  Combination of Capacitors |
 82%
Level 1: 80%+
AIPMT - 2009
Hints
Links

The electric potential at a point (x, y, z) is given by V = -x2y - xz3 + 4.
The electric field E at that point is:
1. E= (2xy + z3)i^ + x2j^ + 3xz2k^
2. E = 2xyi^ + (x2 +y2)j^ +(3xz-y2)k^
3. E = z3i^ + xyzj^ + z2k^
4. E = (2xy- z3)i^ + xy2j^ + 3z2xk^
Subtopic:  Relation between Field & Potential |
 80%
Level 1: 80%+
AIPMT - 2009
Hints
Links

advertisementadvertisement

The electric potential at a point in free space due to a charge \(Q\) coulomb is \(Q\times10^{11}~\text{V}\). The electric field at that point is:
1. \(4\pi \varepsilon_0 Q\times 10^{22}~\text{V/m}\)
2. \(12\pi \varepsilon_0 Q\times 10^{20}~\text{V/m}\)
3. \(4\pi \varepsilon_0 Q\times 10^{20}~\text{V/m}\)
4. \(12\pi \varepsilon_0 Q\times 10^{22}~\text{V/m}\)

Subtopic:  Relation between Field & Potential |
 73%
Level 2: 60%+
AIPMT - 2008
Hints
Links