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

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.

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.

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

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

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

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

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.

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

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

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

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:

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.

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:

Tick the correct statement?

Find the equivalent resistance between the point A and B.

The current I in the circuit shown below is: (All diodes are ideal and identical)

A resistor is connected to a battery of 12 V emf and internal resistance 2 Ω. If the current in the circuit is 0.6 Å, the terminal voltage of the battery is:

A uniform metallic wire having resistance 4 Ω is bent to form a square loop (ABCD) (see figure). A resistance of 2 Ω is connected between points B and D and a battery of 2 V is connected across points A and C as shown in the figure. Now the value of current (I) is:

A room heater is rated 400 W, 220 V. If the supply voltage drops to 200 V, what will be the power consumed (approximately)?

A galvanometer of resistance 100 Ω gives full scale deflection for a current of 1 mA. It is converted into an ammeter of range 0 – 10 Å. The shunt required is:

In a metre bridge experiment (see figure), the positions of the cell, E, and galvanometer, G, are interchanged. We shall observe in the galvanometer:

The current passing through the battery in the given circuit, is:

A wire of resistance R is cut into 8 equal pieces. From these pieces two equivalent resistances are made by adding four of these together in parallel. Then these two sets are added in series. The net effective resistance of the combination is :

A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is:

A wire of length ‘l’ and resistance 100 Ω is divided into 10 equal parts. The first 5 parts are connected in series while the next 5 parts are connected in parallel. The two combinations are again connected in series. The resistance of this final combination is:

The terminal voltage of the battery, whose emf is 10 V and internal resistance 1 Ω, when connected through an external resistance of 4 Ω as shown in the figure is:

Two heaters A and B have power rating of 1 kW and 2 kW, respectively. Those two are first connected in series and then in parallel to a fixed power source. The ratio of power outputs for these two cases is:

Choose the correct circuit which can achieve the bridge balance.

The magnitude and direction of the current in the following circuit is

If the galvanometer G does not show any deflection in the circuit shown, the value of R is given by :

Resistance of a carbon resistor determined from colour codes is (22000 ± 5%) Ω. The colour of third band must be :

The resistance of platinum wire at 0°C is 2Ω and 6.8Ω at 80°C. The temperature coefficient of resistance of the wire is:

10 resistors, each of resistance R are connected in series to a battery of emf E and negligible internal resistance. Then those are connected in parallel to the same battery, the current is increased n times. The value of n is:

Two resistors of resistance, 100 Ω and 200 Ω are connected in parallel in an electrical circuit. The ratio of the thermal energy developed in 100 Ω to that in 200 Ω in a given time is:

A copper wire of length 10 m and radius (10²√π) m has electrical resistance of 10 Ω. The current density in the wire for an electric field strength of 10 (V/m) is:

As the temperature increases, the electrical resistance:

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:

Column-I gives certain physical terms associated with flow of current through a metallic conductor. Column-II gives some mathematical relations involving electrical quantities. Match Column-I and Column-II with appropriate relations.