In a region, the potential is represented by V (x,y,z) = 6x - 8 xy - 8y + 6yz, where V is in volts and x, y, z are in metres. The electric force experienced by a charge of 2 coulomb situated at point (1,1,1) is,

• 6√5 N

• 30 N

• 24 N

• 24 N

A charge Q is enclosed by a Gaussian spherical surface of radius R. If the radius is doubled, then the outward electric flux will 

• be reduced to half

• remain the same

• be doubled

• be doubled

A beam of cathode rays is subjected to crossed Electric (E)  and magnetic field (B). The fields are adjusted such that the beam is not deflected. The specific charge of the cathode rays is given by  

(Where V is the potential difference between cathode and anode)

• B²/2VE²

• 2VB²/E²

• 2VE²/B²

• 2VE²/B²

114.

The square surface of side L metre in the plane of the paper is placed in a uniform electric field E (volt/m) acting along the same place at angle θ with the horizontal side of the square as shown in the figure. The electric flux linked to the surface in unit of V-m is

• EL²

• EL² cos θ

• EL² sin θ

• EL² sin θ

The electric field at a distance 3R/2 from the centre of a charged conducting spherical shell of radius R is E. The electric field at a distance R/2 from the centre of the sphere is

• zero

• E

• E/2

• E/2

The electric field of an electromagnetic wave in free space is given by , where t and x are in seconds and meters respectively. It can be inferred that

1) the wavelength λ is 188.4 m.
2)The wave number k is 0.33 rad/m.
3)The wave amplitude is 10 V /m.
4)The wave is propagating along +x direction

• (3) and (4)

• (1) and (2) 

• (2) and (3)

• (2) and (3)

The electric potential at a point (x, y, Z) is given by

V = - x²y -xz³ + 4

The electric field E at that point is

A hollow cylinder has to charge q coloumb within it. Φ is the electric flux in a unit of voltmeter associated with the curved surface B, the flux linked with the plane surface A in a unit of voltmeter will be:

In a discharge tube ionization of enclosed gas is produced due to collisions between

• positive ions and neutral atoms/molecules

• negative electrons and neutral atoms/molecules

• photons and neutral atoms/molecules

• photons and neutral atoms/molecules

A square surface of side L m is in the plane of the paper. A uniform electric field , also in the plane of the paper, is limited only to the lower half of the square surface, (see figure). The electric flux in SI units associated with the surface is

• 
• 

• zero

• zero