Question
Explain electric field produced by the point electric charge.
✓
Answer
►Let us consider a point charge $Q$ placed in vacuum, at the origin $O$. If we place another point charge q at a point P , where $\overrightarrow{ OP }=\vec{r}$, then the charge $Q$ will exert a force on $q$ as per Coulomb's law.
►The external effect which produces force on charge q , is called electric field of charge $Q$.
►Electric field at point ' P '
$\overrightarrow{ E }(r)=\frac{1}{4 \pi \varepsilon_0} \cdot \frac{ Q }{r^2} \cdot \hat{r}$
Where $\hat{r}$ is the unit vector in the direction of electric field.
►The area around any electric charge or electric charge system where its effect prevails is called the electric field of the electric charge or electric charge system.
OR
►"In the region of an electric charge, or a system of charge, the electrostatic force acting on a unit positive charge placed at some point is called
the electric field of the given electric charge / system of charges."
►Electric field is a vector quantity.
►Its unit is $N / C$ or $V / m .\left( M ^1 L^1 T^{-3} A^{-1}\right)$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
A photographic film is coated with a silver bromide layer. When light fells on this film, silver bromide molecules dissociate end the film records the light there. A minimum of 0.6eV is needed to dissociate a silver bromide molecule. Find the maximum wavelength of light that can be recorded by the film.
Write applications of the resonance phenomenon in the $L - C - R$ series circuit.
→There is no change in the energy of a moving charged particle in a plane magnetic field. Explain, why?
The output of an OR gate is connected to both the inputs of a NAND gate. Draw the logic circuit of this combination of getes and write its truth table.
Answer the following question:
Every metal has a definite work function. Why do all photoelectrons not come out with the same energy if incident radiation is monochromatic? Why is there an energy distribution of photoelectrons?
Every metal has a definite work function. Why do all photoelectrons not come out with the same energy if incident radiation is monochromatic? Why is there an energy distribution of photoelectrons?
An aeroplane travels over a rectangular field 100m × 50m, parallel to its length. What should be the speed of the plane so that the field becomes square in the plane frame?
Write down the Coulomb's law and explain its scalar form.
A barometer tube is 80cm long (above the mercury reservoir). It reads 76cm on a particular day. A small amount of water is introduced in the tube and the reading drops to 75.4cm. Find the relative humidity in the space above the mercury column if the saturation vapour pressure at the room temperature is 1.0cm.
Spring fitted doors close by themselves when released. You want to keep the door open for a long time, say for an hour. If you put a half kg stone in front of the open door, it does not help. The stone slides with the door and the door gets closed. However, if you sandwitch a 20g piece of wood in the small gap between the door and the floor, the door stays open. Explain why a much lighter piece of wood is able to keep the door open while the heavy stone fails.
A molecule of a substance has a permanent electric dipole moment of magnitude $10^{-29} C m$. A mole of this substance is polarised (at low temperature) by applying a strong electrostatic field of magnitude $10^6 V m ^{-1}$. The direction of the field is suddenly changed by an angle of $60^{\circ}$. Estimate the heat released by the substance in aligning its dipoles along the new direction of the field. For simplicity, assume $100 \%$ polarisation of the sample.
→