NEET UG PHYSICS MCQ: CURRENT ELECTRICITY

1 Easy

1 of 1

Application +4 | -1

A uniform wire of length

l

and radius

r

has a resistance of

100\,\Omega

. It is recast into a wire of radius

\frac{r}{2}

. The resistance of new wire will be

View answer and explanation

Correct option: A

1600\Omega

Option A (

1600\Omega

) is correct because when the radius is halved, the area is quartered, and since the volume remains constant, the length becomes four times the original, resulting in a 16-fold increase in resistance.

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In the absence of applied potential, the electric current flowing through a metallic wire is zero because A metallic block has no potential difference applied across it, then the mean velocity of free electrons at absolute temperature

T

is In a thermocouple, which of the following statements is not true (A) The drift velocity of electrons decreases with the increase in the temperature of conductor.
(B) The drift velocity is inversely proportional to the area of cross-section of given conductor.
(C) The drift velocity does not depend on the applied potential difference to the conductor.
(D) The drift velocity of electron is inversely proportional to the length of the conductor.
(E) The drift velocity increases with the increase in the temperature of conductor.
Choose the correct answer from the options given below The mass of ions deposited during a given interval of time in the process of electrolysis depends on The steady current flows in a metallic conductor of non-uniform cross-section. The

\mathrm{quantity}\,\,\mathrm{/}\,\mathrm{quantities}

constant along the length of the conductor

\mathrm{is}\,\,\mathrm{/}\,\,\mathrm{are}