The figure shows some of the electric field lines corresponding to an electric field. The figure suggests:
1. EA > EB > EC
2. EA = EB = EC
3. EA = EC > EB
4. EA = EC < EB
If \(\int_S E.ds = 0\) over a surface, then:
(a) | the electric field inside the surface and on it is zero. |
(b) | the electric field inside the surface is necessarily uniform. |
(c) | the number of flux lines entering the surface must be equal to the number of flux lines leaving it. |
(d) | all charges must necessarily be outside the surface. |
Choose the correct statement(s):
1. (a), (c)
2. (b), (c)
3. (c), (d)
4. (a), (d)
(a) | always continuous. |
(b) | continuous if there is no charge at that point. |
(c) | discontinuous only if there is a negative charge at that point. |
(d) | discontinuous if there is a charge at that point. |
Choose the correct option:
1. | (a), (b) | 2. | (b), (d) |
3. | (c), (d) | 4. | (a), (d) |
The electric flux through the surface,
(i) | (ii) |
(iii) | (iv) |
1. in figure (IV) is the largest
2. in figure (III) is the least
3. in figure (II) is same as in figure (III) but is smaller than figure (IV)
4. is the same for all figures
1. | \(\oint_{s} \vec{E} \cdot d \vec{s} \neq 0\) on any surface. |
2. | \(\oint_{s} \vec{E} \cdot d \vec{s}=0\) if the charge is outside the surface. |
3. | \(\oint_{s} \vec{E} \cdot d \vec{s}=\frac{q}{\varepsilon_{0}}\) if charges of magnitude \(q\) were inside the surface. |
4. | Both (2) and (3) are correct. |
Assertion (A): | Point charges \(q_{1}\) and \(q_{2}\) produce electric field of magnitude \(E_{1}\) and \(E_{2}\) at a point and potential \(V_{1}\) and \(V_{2}\) at the same point. The electric field due to both the charges at that point must be \(E_{1}+E_{2}.\) |
Reason (R): | The electric potential at that point due to both the charges must be \(V_{1}+V_{2}.\) |
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. |
Assertion (A): | Mass of a body decreases slightly when it is negatively charged. |
Reason (R): | Charging is due to the transfer of electrons. |
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. |
Assertion (A): | If electrons in an atom were stationary, then they would fall into the nucleus. |
Reason (R): | Electrostatic force of attraction acts between negatively charged electrons and positive nucleus. |
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. |
Assertion (A): | If the electric field due to a dipole on its axis line at a distance r is E, then the electric field due to a dipole at the same distance at the equatorial line will be E/2. |
Reason (R): | Electric field due to dipole varies inversely as the square of the distance. |
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. | Both (A) and (R) are false. |