Electrostatic important questions and definition with solutions - class 12th physics

As we all know that physics is a difficult subject and electrostatic is a very difficult chapter of class 12th physics , so as to overcome your difficulties we give you a list of all the important electrostatic questions or definition with their answers mentioned with it . 

Q.1: Define one coulomb ?

Ans: charge on a body is said to be one coulomb , if two charges experiences a force of attraction or repulsion of 9 × 10^9N  , when they are separated by a distance of 1m .

Q.2: No , two electric lines of force can intersect each other. why ?

Ans: Two electric lines of force never intersect each other because if they intersect then at the point of intersection there will be two tangents , which is not possible, as the two tangents represents two directions for electric field lines .

Q.3: what is the main practical purpose of the capacitor ?

Ans: To hold more charge at smaller potential difference, so that charge could not leak out due to dielectric breakdown.

Q.4: Define electric dipole moment ?

Ans: The vector sum of the product position vector with point charges is known as dipole moment of a charge distribution about the origin.

Q.5: what is a gold leaf electroscope ?

Ans: A simple apparatus used to detect charge on a body is the gold leaf electroscope .

It can only measure the magnitude of the charge on a body , cannot measure it's polarity .

Q.6: what is the difference between a insulator and a dielectric ?

Ans: Dielectric materials can store energy by getting polarized, whereas some other materials which are insulators cannot be polarized . Again dielectric materials do not conduct electric current like  insulators.

So , in short , all dielectric are insulators but all insulators are not dielectric materials .

Q.7: why does a phonograph-record attract dust particles just after it is cleaned ?

Ans: when a phonograph-record is cleaned, it develops a charge on it surface due to rubbing . This charge attracts the neutral dust particles due to induction .

Q.8: what is potential gradient?

Ans: The rate of change of potential with distance in electric field is called potential gradient.

Potential gradient =dv/Dr

S.I unit = volt/metre

Q.9: what is electrostatic shielding ?

Ans: The process of protecting certain region from external electric field is called electrostatic shielding.

Electrostatic shielding is achieved by enclosing that region in a closed hollow metallic chamber.

Q.10: what is Dielectric constant (k) ?

Ans: The ratio of the strength of the applied electric field to the strength of the reduced value of electric field on placing the Dielectric between the plates of a capacitor is the Dielectric constant (k) .

    

           K=€/€o

I hope that this important questions and definition must be helpful to you for your preparation.

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