ThePrismSolutions

ThePrismSolutions

PHYSICS

CURRENT ELECTRICITY

Q .) It is found that 1020 electrons, each having a charge of 1.6 × 10-19 C, pass from a point X towards another point Y in 0.1s. What is the current and its direction ?

Ans. Here, q = ne = 10 20 × 1.6 × 10 -19 = 16C; t = 0.1s

∴ I = q/t = 16/0.1 = 160A

The direction of convectional current is from the point Y to X.

Q. ) What is conventional current ?

Ans. The Current that flows from poitive pole to negative pole of a cell in the external circuit is called convectional current.

Q. ) What is the direction of conventional current ?

Ans. In an electric circuit, the direction of convectional electric current is form positive to negative terminal of the battery.

Q. ) What is the Significance of direction of electric current ?

Ans. The direction of conventional electric current is opposite to the direction of flow of electrons and the direction of electronic current is same as that of the flow of electrons.

Q. ) Define SI unit of Current? ?

Ans. The current through a conductor is called one ampere, if one coulomb of charge flows through the conductor in one second.

Q. ) Write down the relation between a coulomb and an ampere.

Ans. 1 ampere = 1 coloumb/1 Second

Q .) Define drift velocity of an electron ?

Ans. The drift velocity is defined as the average velocity with which free electrons in a conductor get drifted under the influence of an external electric field applied across the conductor.

Q .) How does the drift velocity of electrons in a metallic conductor vary with increase in temperature ?

Ans. The drift velocity of electrons in a metallic conductor decrease with increase in temperature of the conductor.

Q .) A steady current flows in a metallic conductor of non-uniform cross-section. Explain which of these quantities is constant along the conductor: Current, Current density, electric field and drift speed ?

Ans. Except current, the value of all the quantities depends upon the area of cross-section of the conductor. Hence, only current remains constant, when it flows through a conductor of non-uniform area of the cross-section.

Does the value of resistance of a conductor depend upon the potential difference applied across it or the current passed through it ?

Ans. No, the resistance of a conductor does not depend upon the potential difference applied across it or the current passed through it.



....................

Coming Subjects

  • MATHS FOR JEE MAINS

  • PHYSICS FOR JEE MAINS

  • CHEMISTRY FOR JEE MAINS

  • HISTORY

  • C PROGRAMMING

  • JAVA PROGRAMMING