Which of the following is incorrect about the electrostatic field lines?

1.  These can be never be closed curves

2.  On a conducting surface, the lines are perpendicular

3.  They can pass through a conductor

4.  If the lines are equispaced and parallel to one another, then the field is uniform

 

The conducting shells A and B are arranged as shown below. If the charge on the shell B is q then electric flux linked with the spherical Gaussian surface S is

1.  $\frac{q}{{\epsilon }_0}$

2.  $-\frac{q}{2{\epsilon }_0}$

3.  $-\frac{q}{{\epsilon }_0}$

4.  $\frac{q}{2{\epsilon }_0}$

A particle of mass 2 g and charge 1 $\mu C$ is held at a distance of 1 m from a fixed charge of 1 mC. If the particle is released then its speed, when it is at a distance of 10 m from the fixed charge, is

1.  55 m/s

2.  100 m/s

3.  45 m/s

4.  90 m/s

The insulation property of air breaks down at \(E = 3\times 10^{6}~\text{V/m}\). The maximum charge that can be given to a sphere of diameter \(5\) m is approximately:
1. \(2\times 10^{-5}~\text{C}\)
2. \(2\times 10^{-4}~\text{C}\)
3. \(2\times 10^{-3}~\text{C}\)
4. \(3\times 10^{-3}~\text{C}\)

Given below are two statements: 

Given below are two statements: 

Given below are two statements: 

Some equipotential surfaces are shown in the figure. The electric field at points \(A\), \(B\) and \(C\) are respectively:

An electric field is given by \(\vec E=(\hat i+2\hat j+\hat k)\) N/C. The work done in moving a \(1\) C charge from \(\vec {r_A}=(2\hat i+2\hat j)\) m to \(\vec {r_B}=(4\hat i+\hat j)\) m is:
1. \(8\) J
2. \(4\) J
3. \(-4\) J
4. zero

If n identical drops, each of capacitance C, coalesce to form a single big drop, the capacitance of the big drop will be

1. $n^{3}C$

2. nC 

3. $n^{1/2}C$

4. $n^{1/3}C$