Current Electricity

As shown in the figure, the resistance of a galvanometer G can be found by the half-deflection method. Here the resistance R2 is adjusted such that when the key K is closed the deflection in the galvanometer becomes half of the value as com...

A metal wire of cross-sectional area 0.5 mm2 and length 100 m is connected across a battery of e.m.f. 2 V and internal resistance 1 Ω. The density, atomic mass and electrical conductivity of the metal are 6.35 × 103 kg m−3, 63.5 gm/mole and...

In Circuit-1 and Circuit- 2 shown in the figures, $R_{1}=1 \,\Omega, R_{2}=2 \,\Omega$ and $R_{3}=3 \,\Omega$.

$P_{1}$ and $P_{2}$ are the power dissipations in Circuit-1 and Circuit-2 when the switches $\mathrm{S}_{1}$ and $\mathrm{S}_{2}...

Two resistances $R_{1}=X \Omega$ and $R_{2}=1 \Omega$ are connected to a wire $A B$ of uniform resistivity, as shown in the figure. The radius of the wire varies linearly along its axis from $0.2 \mathrm{~mm}$ at $A$ to $1 \mathrm{~mm}$ at ...

The figure shows a circuit having eight resistances of $1 \Omega$ each, labelled $R_{1}$ to $R_{8}$, and two ideal batteries with voltages $\varepsilon_{1}=12 \mathrm{~V}$ and $\varepsilon_{2}=6 \mathrm{~V}$.

Which of the following stateme...

In the following circuit $C_{1}=12 \mu F, C_{2}=C_{3}=4 \mu F$ and $C_{4}=C_{5}=2 \mu F$. The charge stored in $C_{3}$ is ____________ $\mu C$.

In order to measure the internal resistance r1 of a cell of emf E, a meter bridge of wire resistance R0 = 50\(\Omega\), a resistance R0/2, another cell of emf E/2 (internal resistance r) and a galvanometer G are used in a circuit, as shown ...

In the balanced condition, the values of the resistances of the four arms of a Wheatstone bridge are shown in the figure below. The resistance R3 has temperature coefficient 0.0004\(^\circ\)C-1. If the temperature of R3 is increased by 100$...

Shown in the figure is a semicircular metallic strip that has thickness t and resistivity \(\rho\). Its inner
radius is R1 and outer radius is R2. If a voltage V0 is applied between its two ends, a current I flows
in it. In addition, it is...

In the circuit shown, initially there is no charge on the capacitors and keys S1 and S2 are open. The values of the capacitors are C1 = 10\(\mu\)F, C2 = 30\(\mu\)F and C3 = C4 = 80\(\mu\)F. Which of the statement(s) is/are correct?

Two identical moving coil galvanometers have 10\(\Omega\) resistance and full scale deflection at 2\(\mu\)A current. One of them is converted into a voltmeter of 100 mV full scale reading and the other into an ammeter of 1 mA full scale c...

In the circuit shown below, the key is pressed at time t = 0. Which of the following statement(s) is (are) true?

Consider two identical galvanometers and two identical resistors with resistance R. If the internal resistance of the galvanometers Rc < R/2, which of the following statement(s) about anyone of the galvanometers is(are) true?

An incandescent bulb has a thin filament of tungsten that is heated to high temperature by passing an electric current. The hot filament emits black-body radiation. The filament is observed to break up at random locations after a sufficient...

An infinite line charge of uniform electric charge density l lies along the axis of an electrically conducting infinite cylindrical shell of radius R. At time t = 0, the space inside the cylinder is filled with a material of permittivity e ...

In the following circuit, the current through the resistor R(=2\(\Omega\)) is I amperes. The value of I is :

In an aluminium (Al) bar of square cross section, a square hole is drilled and is filled with iron (Fe) as shown in the figure. The electrical resistivities of Al and Fe are 2.7 \(\times\) 10\(-\)8\(\Omega\) m and 1.0 \(\times\) 10\(-\)7 $...

During an experiment with a metre bridge, the galvanometer shall a null point when the jockey is pressed at 40.0 cm using a standard resistance of 90\(\Omega\), as shown in the figure. The least count of the scale used in the meter bridge i...

A galvanometer gives full scale deflection with 0.006 A current. By connecting it to a 4990 \(\Omega\) resistance, it can be converted into a voltmeter of range 0-30V. If connected to a \({{2n} \over {249}}\Omega\) resistance, it becomes a...

Two ideal batteries of emf V1 and V2 and three resistances R1, R2 and R3 are connected as shown in the figure. The current in resistance R2 would be zero if

If the direct transmission method with a cable of resistance 0.4 \(\Omega\) km\(-\)1 is used, the power dissipation (in %) during transmission is

For the resistance network shown in the figure, choose the correct option(s).

Two batteries of different emfs and different internal resistance are connected as shown. The voltage across AB in volts is __________.

A meter bridge is set up as shown, to determine an unknown resistance X using a standard 10 \(\Omega\) resistor. The galvanometer shows null point when tapping-key is at 52 cm mark. The end-corrections are 1 cm and 2 cm, respectively, for t...

When two identical batteries of internal resistance 1 \(\Omega\) each are connected in series across a resistor R, the rate of heat produced in R is J1. When the same batteries are connected in parallel across R, the rate is J2. If J1 = 2.2...

Consider a thin square sheet of side L and thickness, made of a material of resistivity \(\rho\). The resistance between two opposite faces, shown by the shaded areas in the figure is

To verify Ohm's law, a student is provided with a test resitor RT, a high resistance R1, a small resistance R2, two identical galvanometers G1 and G2, and a variable voltage source V. The correct circuit to carry out the experiment is

Incandescent bulbs are designed by keeping in mind that the resistance of their filament increases with the increase in temperature. If at room temperature, 100, 60 and 40 W bulbs have filament resistances R100, R60 and R40 respectively, th...

For the circuit shown in the figure

STATEMENT - 1
In a Meter Bridge experiment, null point for an unknown resistance is measured. Now, the unknown resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as bef...

Figure shows three resistor configurations R1, R2 and R3 connected to 3 V battery. If the power dissipated by the configuration R1, R2 and R3 is P1, P2 and P3, respectively, then

A resistance of 2 \(\Omega\) is connected across one gap of a metre-bridge (the length of the wire is 100 cm) and an unknown resistance, greater than 2 \(\Omega\), is connected across the other gap. When these resistance are interchanged, t...

Consider a cylindrical element as shown in the figure. The current that flows through the element is I and resistivity of material of the cylinder is $\rho$. Choose the correct option out the following

In the given diagram, a line of force of a particular force field is shown. Out of the following options, it can never represent

An unknown resistance X is to be
determined using resistances R\(_1\), R\(_2\) or R\(_3\). Their corresponding null points are A, B
and C. Find which of the above will give the
most accurate reading and why ?