Current Electricity

In potentiometer experiment, the balancing length is \(8 \mathrm{~m}\) when two cells \(E_1\) and \(E_2\) are joined in series. When two cells are connected in opposition the balancing length is \(4 \mathrm{~m}\). The ratio of the e.m.f. of...

When moving coil galvanometer (MCG) is converted into a voltmeter, the series resistance is '\(n\)' times the resistance of galvanometer. How many times that of MCG the voltmeter is now capable of measuring voltage?

In a given meter bridge, the current flowing through \(40 \Omega\) resistor is

Two cells \(E_1\) and \(E_2\) having equal EMF '\(E\)' and internal resistances \(r_1\) and \(r_2\left(r_1>r_2\right)\) respectively are connected in series. This combination is connected to an external resistance '\(R\)'. It is observed th...

Only \(4 \%\) of the total current in the circuit passes through a galvanometer. If the resistance of the galvanometer is \(G\), then the shunt resistance connected to the galvanometer is

A \(10 \mathrm{~m}\) long wire of resistance \(20 \Omega\) is connected in series with a battery of emf \(3 \mathrm{~V}\) (negligible internal resistance) and a resistance of \(10 \Omega\). The potential gradient along the wire is

A potentiometer wire has length of \(5 \mathrm{~m}\) and resistance of \(16 \Omega\). The driving cell has an e.m.f. of \(5 \mathrm{~V}\) and an internal resistance of \(4 \Omega\). When the two cells of e.m.f.s \(1.3 \mathrm{~V}\) and $$1....

Resistance of a potentiometer wire is \(2 \Omega / \mathrm{m}\). A cell of e.m.f. \(1.5 \mathrm{~V}\) balances at \(300 \mathrm{~cm}\). The current through the wire is

Two resistance \(\mathrm{X}\) and \(\mathrm{Y}\) are connected in the two gaps of a meterbridge and the null points is obtained at \(20 \mathrm{~cm}\) from zero end. When the resistance of \(20 \Omega\) is connected in series with the small...

A potentiometer wire of length \(4 \mathrm{~m}\) and resistance \(5 ~\Omega\) is connected in series with a resistance of \(992 ~\Omega\) and a cell of e.m.f. \(4 \mathrm{~V}\) with internal resistance \(3 ~\Omega\). The length of $$0.75 \m...

In potentiometer experiments, two cells of e. m. f. '\(E_1\)' and '\(E_2\)' are connected in series \(\left(E_1>E_2\right)\), the balancing length is \(64 \mathrm{~cm}\) of the wire. If the polarity of \(E_2\) is reversed, the balancing len...

Potential difference between the points P and Q is nearly

Potential difference between the points P and Q is nearly

Two batteries, one of e.m.f. \(12 \mathrm{~V}\) and internal resistance \(2 \Omega\) and other of e.m.f. \(6 \mathrm{~V}\) and internal resistance \(1 \Omega\), are connected as shown in the figure. What will be the reading of the voltmeter...

A voltmeter of resistance \(150 \Omega\) connected across a cell of e.m.f. \(3 \mathrm{~V}\) reads \(2.5 \mathrm{~V}\). What is the internal resistance of the cell?

If only \(1 \%\) of total current is passed through a galvanometer of resistance '\(G\)' then the resistance of the shunt is

A galvanometer has resistance '\(\mathrm{G}\)' and range '\(\mathrm{V} g\)'. How much resistance is required to read voltage upto '\(\mathrm{V}\)' volt?

In meter bridge experiment, null point was obtained at a distance '\(l\)' from left end. The values of resistances in the left and right gap are doubled and then interchanged. The new position of the null point is

A galvanometer of resistance \(200 \Omega\) is to be converted into an ammeter. The value of shunt resistance which allows \(3 \%\) of the mains current through the galvanometer is equal to (nearly)

In the following network, the current through galvanometer will

In a potentiometer experiement, when three cells \(\mathrm{A}, \mathrm{B}\) and \(\mathrm{C}\) are connected in series, the balancing length is found to be \(420 \mathrm{~cm}\). If cells \(\mathrm{A}\) and \(\mathrm{B}\) are connected in se...

The current drawn from the battery in the given network is (Internal resistance of the battery is negligible)

In the following electrical network, the value of 1 is

A balanced bridge is shown in the circuit diagram. The metre bridge wire has resistance \(1 \Omega \mathrm{m}^{-1}\). The current drawn from the battery is (Internal resistance of battery is negligible)

In potentiometer experiment, cells of e.m.f. '\(E_1\)' and '\(E_2\)' are connected in series \(\left(E_1>E_2\right)\) the balancing length is \(64 \mathrm{~cm}\) of the wire. If the polarity of \(E_2\) is reversed, the balancing length beco...

In the given circuit, the current in 8\(\Omega\) resistance is 1.5 A. The total current (I) flowing in the circuit is

To determine the internal resistance of a cell by using a potentiometer, the null point is at \(1 \mathrm{~m}\) when shunted by \(3 \Omega\) resistance and at a length \(1.5 \mathrm{~m}\), when cell is shunted by \(6 \Omega\) resistance The...

The Kirchhoff's current law and voltage law are respectively based upon the conservation of

If a current flowing in a coil is reduced to half of its initial value, the relation between the new energy \(\left(E_2\right)\) and the original energy \(\left(E_1\right)\) stored in the coil will be

In a wheatstone's bridge, three resistances \(\mathrm{P}, \mathrm{Q}\) and \(\mathrm{R}\) are connected in the three arms and the fourth arm is formed by two resistances \(S_1\) and \(S_2\) connected in parallel. The condition for the bridg...

Kirchhoff's current and voltage law are respectively based on the conservation of

In a potentiometer experiment, the balancing length for a cell is \(240 \mathrm{~cm}\). On shunting the cell with a resistance of \(2 \Omega\), the balancing length becomes half the initial balancing length. The internal resistance of the c...

Two wires '\(\mathrm{A}\)' and '\(\mathrm{B}\)' of equal length are connected in left and right gap respectively of meter bridge, null point is obtained at \(40 \mathrm{~cm}\), from the left end. Diameters of the wires '\(A\)' and '\(B\)' a...

In a meter bridge experiment, the balance point is obtained at length \(\ell_1 \mathrm{~cm}\) from left end when resistances in the left gap and right gap are \(5 \Omega\) and \(R \Omega\) respectively. When the resistance \(R\) is shunted ...

A current through 1 \(\Omega\) resistance in the following circuit is

A moving coil galvanometer is converted into an ammeter, reading upto \(0.04 \mathrm{~A}\) by connecting a shunt of resistance '\(3 \mathrm{r}\)' across it and then into an ammeter reading upto \(0.8 \mathrm{~A}\), when a shunt of resistanc...

Consider the circuit shown in the figure. The value of current 'I' is

A galvanometer of resistance \(50 \Omega\) is converted to an ammeter. After shunting, the effective resistance of ammeter is \(2.5 \Omega\). The value of shunt is

In potentiometer experiment, null point is obtained at a particular point for a cell on potentiometer wire '\(\mathrm{x}\)' cm long. If length of potentiometer wire is increased by few centimeter without changing the cell, the balancing len...

A galvanometer has resistance '\(\mathrm{G}\)' \(\Omega\) and '\(\mathrm{I}_{\mathrm{g}}\)' is current flowing through it which produces full scale deflection. '\(\mathrm{S}_1\)' is the value of shunt which converts it into an ammeter of ra...

Two galvanometers $A$ and $B$ require currents of 4 mA and 7 mA , respectively to produce the same deflection of 20 divisions. If $S_A$ and $S_B$ are their sensitivities respectively, then

A 10 m long wire of resistance $20 \Omega$ is connected in series with a battery of emf 3 V and a resistance of $10 \Omega$. The potential gradient along the wire in $\mathrm{V} / \mathrm{m}$ is

Two cells having unknown emfs $E_1$ and $E_2$ $\left(E_1>E_2\right)$ are connected in potentiometer circuit, so as to assist each other. The null point obtained is at 490 cm from the higher potential end. When cell $E_2$ is connected, so as...

A milliammeter of resistance $40 \Omega$ has a range $0-30 \mathrm{~mA}$. What will be the resistance used in series to convert it into voltmeter of range $0-15 \mathrm{~V}$ ?

A potentiometer wire is \(4 \mathrm{~m}\) long and potential difference of \(3 \mathrm{~V}\) is maintained between the ends. The emf of the cell, which balances against a length of \(100 \mathrm{~cm}\) of the potentiometer wire is

Two wires \(A\) and \(B\) of equal lengths are connected in left and right gap of a meter bridge, null point is obtained at \(40 \mathrm{~cm}\) from left end. Diameters of the wire \(A\) and \(B\) are in that ratio \(3: 1\). The ratio of sp...

An ammeter of resistance \(20 \Omega\) gives full scale deflection, when \(1 \mathrm{~mA}\) current flows through it. What is the maximum current that can be measured by connecting 4 resistors each of \(16 \Omega\) in parallel with the amme...

A circular coil of radius \(R\) has a resistance of \(40 \Omega\). Figure shows two points \(P\) and \(Q\) on the circumference separated by a distance \(\frac{\pi R}{2}\) which are connected to a 16 V battery with internal resistance of $$...

Which of the following instruments is not a direct reading instrument?

In conversion of moving coil galvanometer into an ammeter of required range, the resistance of ammeter, so formed is
[\(S=\) shunt and \(G=\) resistance of galvanometer]