A new flashlight cell of emf 1.5 volts gives a current of 15 amps, when connected directly to an ammeter of resistance 0.04 Ω. The internal resistance of cell is

In meter bridge, the balancing length from left end when standard resistance of 1 Ω is in right gap is found to be 20 cm. The value of unknown resistance is

A Daniel cell is balanced on 125 cm length of a potentiometer wire. When the cell is short circuited with a 2 Ω resistance, the balancing length obtained is 100 cm. Internal resistance of the cell will be

Equal potentials are applied on an iron and copper wire of same length. In order to have same current flow in the wire, the ratio (r_iron/r_copper) of their radii must be [Given that specific resistance of iron = 1.0 x 10^-7 Ωm and that of copper = 1.7 x 10^-8 Ωm]

A metal rod of length 10 cm and a rectangular cross-section of 1cm x ½ cm is connected to a battery across opposite faces. The resistance will be

Kirchhoff’s II law for the electric network is based on:

WSB experiment is most sensitive, when:

In a Whetstone’s bridge, all the four arms have equal resistance R. If resistance of the galvanometer arm is also R, then equivalent resistance of the combination is-

For a cell of e.m.f. 2 V, a balance is obtained for 50 cm of the potentiometer wire. If the cell is shunted by a 2 ohm resistor and the balance is obtained across 40 cm of the wire, then the internal resistance of the cell is :

For a cell, the terminal potential difference is 3.6 V, when the circuit is open. If the potential difference reduces to 3 V, when cell is connected to a resistance of 5 Ω, the internal resistance of cell is (in ohm) :

The temperature coefficient of resistance for a wire is 00125 /˚C . At 27°K its resistance is 1 ohm. The temperature at which the resistance becomes 2 ohm is

Drift velocity v_d varies with the intensity of electric field as per the relation :

A cell of internal resistance 3 ohm and emf 10 volt is connected to a uniform wire of length 500 cm and resistance 3 ohm. The potential gradient in the wire is:

In a Whetstone’s bridge, all the four arms have equal resistance R. If resistance of the galvanometer arm is also R, then equivalent resistance of the combination is

Across a wire of length l and thickness d, a P.D of V is applied. If the P.D. is doubled then the drift velocity becomes-

Which is the dimensional formula for resistance from the given below?

Two electric bulbs whose resistances are in the ratio of 1:2 are connected in parallel to a constant voltage source the power dissipated in them have the ratio-

The resistance of a copper coil is 4. 64Ω at40 ⁰C and 5.6Ω at 100 ⁰C. Its resistance at 0 ⁰C will be-

A uniform wire is cut into 10 segments increasing in length in equal steps. The resistance of shortest segment is R and the resistance of the other segments increases in steps of 6 Ω. If the resistance of the longest segment is 3R, then the value of R is:

Current provided by a battery is maximum when

An energy source will supply a constant current into the load if its internal resistance is

If in the experiment of Wheatstone's bridge, the positions of cells and galvanometer are interchanged, then balance points will

For comparing the e.m.f.'s of two cells with a potentiometer, a standard cell is used to develop a potential gradient along the wires. Which of the following possibilities would make the experiment unsuccessful

The resistance of an ideal ammeter is

A galvanometer has 30 divisions and a sensitivity 16A / div. It can be converted into a voltmeter to read 3 V by connecting

A 10 m long wire of 20 resistance is connected with a battery of 3 volt e.m.f. (negligible internal resistance) and a 10  resistance is joined to it is series. Potential gradient along wire in volt per meter is

Specific resistance of a conductor increases with :–

When no current flows through a conductor :-

What is the effect on the product of resistivity and conductivity of a conductor when its temperature is increased?