The electric field at the surface of a black box indicates that the net outward flux through the surface of the box is \(8.0\times10^{3}\) N-m²/C. What is the net charge inside the box?
1. \(1.01\) \(\mu\)C
2. \(0.01\) \(\mu\)C
3. \(0.03\) \(\mu\)C
4. \(0.07\) \(\mu\)C

A point charge + 10 μC is at a distance 5 cm directly above the centre of a square of side 10 cm, as shown in the figure. What is the magnitude of the electric flux through the square?

1. $3.18\times {10}^5 N m^2 C^{-1}$

2. $2.10\times {10}^5 N m^2 C^{-1}$

3. $1.03\times {10}^5 N m^2 C^{-1}$

4. $1.88\times {10}^5 N m^2 C^{-1}$

A point charge of 2.0 μC is at the center of a cubic Gaussian surface 9.0 cm on edge. What is the net electric flux through the surface?

1. 2.26 × 10⁵  N  m² C^-1
2. 2.09 × 10⁵  N  m² C^-1
3. 4.33 × 10⁵  N  m² C^-1
4. 4.71 × 10⁵  N  m² C^-1   

A point charge causes an electric flux of $-1.0\times {10}^3 N m^2/C$ to pass through a spherical Gaussian surface of 10.0 cm radius centered on the charge. If the radius of the Gaussian surface were doubled, how much flux would pass through the surface?

1. - 2.0×10³  N m²/ C
2. - 1.0 ×10³ N m²/ C
3.  2.0 ×10³  N  m²/ C
4.   0

A conducting sphere of radius \(10\) cm has an unknown charge. If the electric field, \(20\) cm from the centre of the sphere is \(1.5\times10^3\) N/C and points radially inward, what is the net charge on the sphere?
1. \(-5.70\) nC
2. \(-6.67\) nC
3. \(6.67\) nC
4. \(5.70\) nC

A uniformly charged conducting sphere of 2.4 m diameter has a surface charge density of $80.0 \mu C/m^2$. The charge on the sphere is:

1. 2 .077 × 10^-3 C
2. 2. 453 × 10^-3C
3. 1. 447 × 10^-3C
4. 3. 461 × 10^-3C

 

An infinite line charge produces a field of \(9\times10^{4}~\text{N/C}\) at a distance of \(2~\text{cm}\). The linear charge density is:
1. \(0.1~\mu\text{C/m}\)
2. \(100~\mu\text{C/m}\)
3. \(1.0~\mu\text{C/m}\)
4. \(10~\mu\text{C/m}\)

Two large, thin metal plates are parallel and close to each other. On their inner faces, the plates have surface charge densities of opposite signs and of magnitude 17.0 x 10^-22 C/m². The electric field between the plates is: 

1. 0.96 × 10^-10   N/C
2. 1.92 × 10^{- 10}   N/C
3. 0
4. 3.84 × 10^-10   N/C

An oil drop of 12 excess electrons is held stationary under a constant electric field of $2.55\times {10}^{-4} N C^{-1}$. The density of the oil is $1.26 g c{m}^{-3}$. The radius of the drop is:

1. \(9.82\times10^{-4}\) mm
2. \(9.82\times10^{-7}\) mm
3. \(8.92\times10^{-4}\) mm
4. \(8.92\times10^{-7}\) mm

 

Which among the curves shown in the figure represents electrostatic field lines?
 

1.		2.
3.		4.