When the length and area of cross-section both are doubled, then its resistance :

(1) Will become half

(2) Will be doubled

(3) Will remain the same

(4) Will become four times

Concept Questions :-

Derivation of Ohm's law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The resistivity of a wire :

(1) Increases with the length of the wire

(2) Decreases with the area of cross-section

(3) Decreases with the length and increases with the cross-section of the wire

(4) None of the above statement is correct

Concept Questions :-

Derivation of Ohm's law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Drift velocity vd varies with the intensity of electric field as per the relation

(1) ${v}_{d}\propto E$

(2) ${v}_{d}\propto \frac{1}{E}$

(3) vd = constant

(4) ${v}_{d}\propto {E}^{2}$

Concept Questions :-

Current and current density
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In a conductor 4 coulombs of charge flows for 2 seconds. The value of electric current will be :

(1) 4 volts

(2) 4 amperes

(3) 2 amperes

(4) 2 volts

Concept Questions :-

Current and current density
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The specific resistance of a wire is ρ, its volume is 3 m3 and its resistance is 3 ohms, then its length will be

(1) $\sqrt{\frac{1}{\rho }}$

(2) $\frac{3}{\sqrt{\rho }}$

(3) $\frac{1}{\rho }\sqrt{3}$

(4) $\rho \sqrt{\frac{1}{3}}$

Concept Questions :-

Derivation of Ohm's law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

When a piece of aluminum wire of finite length is drawn through a series of dies to reduce its diameter to half its original value, its resistance will become :

(1) Two times

(2) Four times

(3) Eight times

(4) Sixteen times

Concept Questions :-

Derivation of Ohm's law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Through a semiconductor, an electric current is due to drift off:

(1) Free electrons

(2) Free electrons and holes

(3) Positive and negative ions

(4) Protons

Concept Questions :-

Current and current density
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A metallic block has no potential difference applied across it, then the mean velocity of free electron is (T = absolute temperature of the block) :

(1) Proportional to T

(2) Proportional to $\sqrt{T}$

(3) Zero

(4) Finite but independent of temperature

Concept Questions :-

Current and current density
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The specific resistance of all metals is most affected by :

(1) Temperature

(2) Pressure

(3) Degree of illumination

(4) Applied magnetic field

Concept Questions :-

Current and current density
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The positive temperature coefficient of resistance is for :

(1) Carbon

(2) Germanium

(3) Copper

(4) An electrolyte

Concept Questions :-

Current and current density