Question

In a certain region of space with volume 0.2 m3,
the electric potential is found to be 5 V throughout.
The magnitude of electric field in this region is:
(1) 1 N/C
(2) 5 N/C
(
3)
zero
(4)
0.5 N/C
an
Con at pressure of​

Answer 1

Answer:

Dipole moment of the system, p=q×dl=−10

−7

Cm

Rate of increase of electric field per unit length,

dl

dE

=10

+5

NC

−1

Force (F) experienced by the system is given by the relation,

F=qE

F=q

dl

dE

×dl

=p×

dl

dE

=10

−7

×10

−5

=−10

−2

N

The force is −10

−2

N in the negative z-direction i.e., opposite to the direction of electric field. Hence, the angle between electric field and dipole moment is 180

o

.

Torque (τ) is given by the relation,

T=pEsin180

o

=0

Therefore, the torque experienced by the system is zero.

Answer 2

Correct Question:

In a certain region of space with volume 0.2m³ the electric potential is found to be 5V throughout.

The magnitude of electric field inthis region is:(1)0.5 N/C (2)1 N/C (3)5 N/C (4)zero

(NEET -2020)

Calculation:

Let the Electric Field in the region be E

We know that :

$\therefore \: E = - \dfrac{ \partial V}{ \partial r}$

But , the question says that the electric potential in the whole specified space is constant and equal to 5 V throughout the space.

This means that $\partial V$=0 because there is no change in potential w.r.t distance from reference.

$= > \: E = - \dfrac{ 0}{ \partial r}$

$= > \: E = 0 \: N{C}^{-1}$

So, final answer is:

$\boxed{ \bf{\: E = 0 \: N{C}^{-1}}}$