Current Electricity

The number of electrons moving per second through the filament of a lamp of $60$ W operating at $120$ V is nearly $(e = 1.6 \times 10^{-19}\text{ C})$ _____________.

Given below are two statements:Statement-I: The resistivity of a conductor is independent of its temperature.Statement-II: The resistivity of a semiconductor decreases with increase in temperature.Select the correct option.

Current flowing through a wire decreases linearly from $10$ A to zero in $4$ s as shown in the graph. Find the total charge flowing through the wire in the given time interval.

In a conducting region, $10^{19}$ electrons and $10^{19}$ protons move to the left, while $10^{19}$ $\alpha$-particles move to the right per second. The resulting electric current is $(e = 1.6 \times 10^{-19}\text{ C})$ _________

Which of the following circuits is correct for verification of Ohm's law?

In the figure, the values of currents $I_1, I_2$ and $I_3$ respectively are

The variations of resistivity $\rho$ with absolute temperature T for three different materials $\mathrm{X}, \mathrm{Y}$ and Z are shown in the graph below. Identify the materials $\mathrm{X}, \mathrm{Y}$ and Z .

Two similar galvanometers are covered into an ammeter and a milliammeter. The shunt resistance of ammeter as compared to the shunt resistance of milliammeter will be

Two cells of emfs $E_1$ and $E_2$ and internal resistances $r_1$ and $r_2\left(E_2>E_1\right.$ and $\left.r_2>r_1\right)$ respectively, are connected in parallel as shown in figure. The equivalent emf of the combination is $\mathrm{E}_{\tex...

In an experiment to determine the figure of merit of a galvanometer by half deflection method, a student constructed the following circuit.

He unplugged a resistance of $5200 \Omega$ in R . When $\mathrm{K}_1$ is closed and $\mathrm{K}_2$ ...

\(\text { In the following circuit, the terminal voltage across the cell is }\)

The graph between variation of resistance of a metal wire as a function of its diameter keeping other parameters like length and temperature constant is

The range of electrical conductivity $(\sigma)$ and resistivity $(\rho)$ for metals, among the following, is

Given, a current carrying wire of non-uniform cross-section, which of the following is constant throughout the length of wire?

In an experiment to determine the temperature coefficient of resistance of a conductor, a coil of wire $X$ is immersed in a liquid. It is heated by an external agent. A meter bridge set up is used to determine resistance of the coil $X$ at ...

The electric current flowing through a given conductor varies with time as shown in the graph below. The number of free electrons which flow through a given cross-section of the conductor in the time interval $0 \leq t \leq 20 \mathrm{~s}$ ...

The $I-V$ graph for a conductor at two different temperatures $100^{\circ} \mathrm{C}$ and $400^{\circ} \mathrm{C}$ is as shown in the figure. The temperature coefficient of resistance of the conductor is about (in per degree Celsius)

In the circuit shown, the end $A$ is at potential $V_0$ and end $B$ is grounded. The electric current $I$ indicated in the circuit is

An electric blub of $60 \mathrm{~W}, 120 \mathrm{~V}$ is to be connected to 220 V source. What resistance should be connected in series with the bulb, so that the bulb glows properly?

E is the electric field inside a conductor whose material has conductivity $\sigma$ and resistivity $\rho$. The current density inside the conductor is $\mathbf{J}$. The correct form of Ohm's law is

A moving coil galvanometer is converted into an ammeter of range 0 to \(5 \mathrm{~mA}\). The galvanometer resistance is \(90 \Omega\) and the shunt resistance has a value of \(10 \Omega\). If there are 50 divisions in the galvanometer-turn...

The four bands of a colour coded resistor are of the colours grey, red, gold and gold. The value of the resistance of the resistor is

The resistance of a carbon resistor is \(4.7 ~\mathrm{k} \Omega \pm 5 \%\). The colour of the third band is

The equivalent resistance between the points A and B in the following circuit is

Ten identical cells each emf \(2 \mathrm{~V}\) and internal resistance \(1 ~\Omega\) are connected in series with two cells wrongly connected. A resistor of \(10 ~\Omega\) is connected to the combination. What is the current through the res...

For a given electric current the drift velocity of conduction electrons in a copper wire is \(v_d\) and their mobility is \(\mu\). When the current is increased at constant temperature

A wire of resistance \(R\) is connected across a cell of emf \((\varepsilon)\) and internal resistance \((r)\). The current through the circuit is \(I\). In time \(t\), the work done by the battery to establish the current \(I\) is

If voltage across a bulb rated \(220 \mathrm{~V}, 100 \mathrm{~W}\) drops by \(2.5 \%\) of its rated value, then the percentage of the rated value by which the power would decrease is

A galvanometer of resistance \(50 \Omega\) is connected to a battery \(3 \mathrm{~V}\) along with a resistance \(2950 \Omega\) in series. A full scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this defle...

A wire of a certain material is stretched slowly by \(10 \%\). Its new resistance and specific resistance becomes respectively

When a metal conductor connected to left gap of a meter bridge is heated, the balancing point

In an atom electrons revolve around the nucleus along a path of radius \(0.72\mathop A\limits^o\) making \(9.4 \times 10^{18}\) revolutions per second. The equivalent currents is [given, \(e=1.6 \times 10^{-19} \mathrm{C}\)]

10 identical cells each potential \(E\) and internal resistance \(r\) are connected in series to form a closed circuit.

Determine the potential difference across three cells using an ideal voltmeter.

Wire bound resistors are made by winding the wires of an alloy of

A charged particle is moving in an electric field of \(3 \times 10^{-10} \mathrm{Vm}^{-1}\) with mobility \(2.5 \times 10^6 \mathrm{~m}^2 / \mathrm{V}-\mathrm{s}\), its drift velocity is

In the given arrangement of experiment on meter bridge, if \(A D\) corresponding to null deflection of the galvanometer is \(X\), what would be its value if the radius of the wire \(A B\) is doubled?

Consider an electrical conductor connected across a potential difference \(V\). Let \(\Delta q\) be a small charge moving through it in time \(\Delta t\). If \(I\) is the electric current through it,
I. the kinetic energy of the charge incr...

A wire of resistance \(3 \Omega\) is stretched to twice its original length. The resistance of the new wire will be

A copper wire of length \(1 \mathrm{~m}\) and uniform cross-sectional area \(5 \times 10^{-7} \mathrm{~m}^2\) carries a current of \(1 \mathrm{~A}\). Assuming that, there are \(8 \times 10^{28}\) free electrons per \(\mathrm{m}^3\) in coppe...

\(I-V\) characteristic of a copper wire of length \(L\) and area of cross-section \(A\) is shown in figure. The slope of the curve becomes

Each resistance in the given cubical network has resistance of \(1 \Omega\) and equivalent resistance between \(A\) and \(B\) is

A potentiometer has a uniform wire of length \(5 \mathrm{~m}\). A battery of emf \(10 \mathrm{~V}\) and negligible internal resistance is connected between its ends. A secondary cell connected to the circuit gives balancing length at $$200 ...

A car has a fresh storage battery of emf \(12 \mathrm{~V}\) and internal resistance \(2 \times 10^{-2} \Omega\). If the starter motor draws a current of \(80 \mathrm{~A}\). Then, the terminal voltage when the starter is On is

A metal rod of length \(10 \mathrm{~cm}\) and a rectangular cross-section of \(1 \mathrm{~cm} \times \frac{1}{2} \mathrm{~cm}\) is connected to a battery across opposite faces. The resistance will be

The colour code for a carbon resistor of resistance \(0.2 \mathrm{k} \Omega \pm 10 \%\) is

The variation of terminal potential difference \(V\) with current flowing through a cell is as shown. The emf and internal resistance of the cell are

In the given circuit, the current through 2\(\Omega\) resistor is

The readings of ammeter and voltmeter in the following circuit are respectively

In a potentiometer experiment, the balancing point with a cell is at a length \(240 \mathrm{~cm}\). On shunting the cell with a resistance of \(2 \Omega\), the balancing length becomes \(120 \mathrm{~cm}\). The internal resistance of the ce...

Kirchhoff 's junction rule is a reflection of