Current Electri...

In each of the follwing questions, match column I and column II and select the correct match out of the four given choices.

In each of the follwing questions, match column I and column II and select the correct match out of the four given choices

Match the following two columns.

Match the physical quantities given in column I with their dimensional formulae given in column II –I stands for the dimesion of current.

The length of a potentiometer wire is 600cm and it carries a current of 40m A for cell of emf 2V and internal resistance 10Ω, the null point is found to be at 500cm on connecting a voltmeter across the cell, the balancing length is decreased by 10 cm
The voltmeter reading will be.

The length of a potentiometer wire is 600cm and it carries a current of 40m A for cell of emf 2V and internal resistance 10Ω, the null point is found to be at 500cm on connecting a voltmeter across the cell, the balancing length is decreased by 10 cm
The resistance of the voltmeter is

Assertion: There is no current in the metals in the absence of electric field.
Reason: Motion of free electrons is random.

Assertion: the drift velocity of electrons in a metallic wire will decrease, if the tempreature of the wire is increased
Reason: On increasing temperature, conductivity of metallic wire decreases

Assertion: A potentiometer of longer length is used for acaurate measurement.
Reason: The potential gradient for a potentiometer of longer length with a given source of e.m.f become small.

Assertion: The 200w bulbs glow with more brightness than 100w bulbs.
Reason: A 100w bulb has more resistance than a 200w bulb.