NEET Physics Current Electricity Class 12 Questions

A galvanometer of resistance 100 Ω gives full scale deflection for a current of 1.0 mA. It is converted into an ammeter of range 0-1 Å. The resistance of the ammeter will be close to

Temperature dependence of resistivity ρ(T) of semiconductors, insulators and metals is significantly based on the following factors : (1) number of charge carriers can change with temperature T (2) time interval between two successive collisions can depend on T.

A wheatstone bridge is used to determine the value of unknown resistance X by adjusting the variable resistance Y as shown in the figure. For the most precise measurement of X, the resistances P and Q :

A cell having an emf ε and internal resistance r is connected across a variable external resistance R. As the resistance R is increased, the plot of potential difference V across R is given by

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Alloys such as constantan and manganin are used in making standard resistance coils. Reason R: Constantan and manganin have very small value of temperature coefficient of resistance. In the light of the above statements, choose the correct answer from the options given below.

Two conductors are made of the same material and have the same length. Conductor A is solid wire of diameter 1 mm. Conductor B is hollow tube of outer diameter 2 mm and inner diameter 1 mm. The ratio of resistance RA to RB.

The resistance of a wire is 10 Ω. Its length is increased by 10% by stretching. The new resistance will now be

In a metallic conductor, under the effect of applied electric field, the free electrons of the conductor

Given below are two statements:

Statement I: The equivalent resistance of resistors in a series combination is smaller than least resistance used in the combination.

Statement II: The resistivity of the material is independent of temperature.

In the light of the above statements, choose the correct answer from the options given below:

The current in the given circuit is

A battery supplies 0.9 Å current through a 2 Ω resistor and 0.3 Å current through a 7 Ω resistor when connected one by one. The internal resistance of the battery is

The resistor of resistance 'R' is connected to 25 V supply and heat produced in it is 25 J/sec. The value of R is

The range of voltmeter of resistance 300 $\Omega$ is 5 V. The resistance to be connected to convert it into an ammeter of range 5 Å is

Considering a group of positive charges, which of the following statements is correct?

Statement 1: No work is required to be done to move a test charge between any two points on an equipotential surface.

Statement 2: Electric lines of force at the equipotential surfaces are mutually perpendicular to each other.

In an atom electrons revolve around the nucleus along a path of radius 0.72 Å making 9.4 × 10¹⁸ revolution per second. The equivalent current is (e = 1.6 × 10⁻¹⁹)

As shown in the figure, the voltmeter reads 2V across 5 Ω resistor. The resistance of the voltmeter is ____ Ω.

Two resistors of resistances R₁ = (100 ± 3) Ω and R₂ = (200 ± 4) Ω are connected in parallel. The equivalent resistance of the parallel combination is

Two wires of equal length are made of two materials whose resistivities ρ₁ and ρ₂. They are connected in series. The equivalent resistivity of the combination is

Given below are two statements:

Statement I: A uniform wire of resistance 80 Ω is cut into four equal parts. These parts are now connected in parallel. The equivalent resistance of the combination will be 5 Ω.

Statement II: Two resistances 2R and 3R are connected in parallel in a electric circuit. The value of thermal energy developed in 3R and 2R will be in the ratio 3:2.

In the light of the above statements, choose the most appropriate answer from the option given below

The equivalent resistance of the circuit shown in figure between the points A and B if Vₐ < Vᵦ is

A storage battery of emf 8.0 V and internal resistance 0.5 Ω is being charged by a 120 V dc supply using a series resistor of 15.5 Ω. What is the terminal voltage of the battery during charging?

The equivalent resistance of the circuit shown below between points a and b is:

In the given figure, a battery of emf E is connected across a conductor PQ of length 'l' and different area of cross-sections having radii r₁ and r₂ (r₂ < r₁). Choose the correct option as one moves from P to Q:

Assertion: If the length of the conductor is doubled, the drift velocity will become half of the original value (keeping potential difference unchanged). Reason: At constant potential difference, drift velocity is inversely proportional to the length of the conductor.

Tick the correct statement?

Find the equivalent resistance between the point A and B.

What is the relationship between current density (j) and electric field (E) as stated in Ohm's Law?

What is the relationship between resistance (R), resistivity (ρ), length (l), and cross-sectional area (A) of a conductor?

What is the term used to describe the potential difference between the terminals of a cell?

What is the equation for the power loss in a conductor carrying a current I?

Which of the following materials is mentioned as a homogeneous conductor that obeys Ohm's law within certain electric field values?

How does the resistivity of semiconductors change with increasing temperature?

What is the power loss in a conductor of resistance R carrying a current I, according to Ohm's law?

What is the unit of electric resistance?

What is the steady temperature of the heating element connected to a 230 V supply, if it draws an initial current of 3.2 A and settles to a steady value of 2.8 A, considering the room temperature is 27.0 °C?

What is the expression for drift velocity of electrons in a conductor?

What is the term used to describe the average velocity of electrons due to an electric field in a conductor?

What is the unit of electric current as defined in the SI system?

What is the relationship between voltage (V) and current (I) in a material that obeys Ohm's law?

What does the loop rule state regarding the algebraic sum of changes in potential around any closed loop?

What is the condition for a Wheatstone bridge to achieve balance and provide zero deflection in the galvanometer?

Which of the following statements about resistance and current in a circuit is correct?

Which of the following statements about series combinations of cells is correct?

Which of the following statements about electric circuits is correct?

Which of the following statements about the electromotive force (emf) and internal resistance in a circuit are correct?

Which of the following statements about the Wheatstone bridge and its operation is correct?

Which of the following statements about the equivalent resistance of resistors in a network is correct?

Which combination of statements about the behavior of cells in an electric circuit is correct?

Which of the following statements about Ohm's law and resistance is correct?