Question 1 :
The resistance of 1 A ammeter is 0.018 &Omega;. To convert it into 10 A ammeter, the shunt resistance required will be<br>

Question 2 :
A car has a fresh battery of e.m.f. {tex}12 V{/tex} and internal resistance of {tex} 0.05 \Omega {/tex}. If the starter motor draws a current of {tex}90{/tex} {tex} A , {/tex} the terminal voltage when the starter is on will be

Question 3 :
In the given current distribution what is the value of {tex} I {/tex} <br><img style='object-fit:contain' src="https://data-screenshots.sgp1.digitaloceanspaces.com/5dc14f00b27c0666ff0b3126.jpg" />

Question 4 :
A wire of resistance 4 Ω is stretched to twice its original length. What is the resistance of the wire now?

Question 7 :
If six identical cells each having an e.m.f. of {tex} 6 \mathrm { V } {/tex} are connected in parallel, the e.m.f. of the combination is

Question 8 :
The length of a given cylindrical wire is increased by {tex} 100 \% {/tex}. Due to the consequent decrease in diameter the change in the resistance of the wire will be

Question 9 :
A battery is charged at a potential of {tex} 15 \mathrm { V } {/tex} for 8 {tex}hours{/tex} when the current flowing is {tex} 10 \mathrm { A } {/tex}. The battery on discharge supplies a current of {tex} 5 \mathrm { A } {/tex} for 15 {tex}hours{/tex}. The mean terminal voltage during discharge is {tex} 14\mathrm { V } {/tex}. The {tex}"Watt-hour"{/tex} efficiency of the battery is

Question 10 :
The current flowing in a coil of resistance {tex} 90 \Omega {/tex} is to be reduced by {tex} 90 \% {/tex}. What value of resistance should be connected in parallel with it

Question 11 :
Nichrome or Manganin is widely used in wire bound standard resistors because of their<br>

Question 12 :
Consider the circuit given here with the following parameters.<br> E.M.F. of the cell {tex} = 12 {/tex} {tex} V {/tex}. Internal resistance of the cell {tex} = 2 \Omega {/tex} Resistance {tex} R = 4 \Omega {/tex} <br> <img style='object-fit:contain' src='https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5dc139dfec8cf4127b9326f6' /> <br>Which one of the following statements is true

Question 13 :
The momentum acquired by the electron in 10 cm of the wire when a current of 1 A starts to flow, is -<br>

Question 14 :
The potential difference across the {tex} 100 \Omega {/tex} resistance in the following circuit is measured by a voltmeter of {tex} 900 \Omega {/tex} resistance. The percentage error made in reading the potential difference is<br> <img style='object-fit:contain' src="https://data-screenshots.sgp1.digitaloceanspaces.com/5dc018ddb27c0666ff0b2c22.jpg" />

Question 15 :
Resistivity of iron is 1 &times; 10^-7ohm-metre. The resistance of the given wire of a particular thickness and length is 1 &Omega;. If the diameter and length of the wire both are doubled, the resistivity will be - <br>

Question 16 :
A 1-meter length 22 gauge of copper wire has a current of 1 mA passing through it $1.7\times10^8m$<span class="MathJax"><span class="MJX_Assistive_MathML">=1.7108m</span></span> in this wire.

Question 17 :
A current I flows through a uniform wire of diameter d when the mean electron drift velocity is<br/>V. The same current will flow through a wire of diameter d/2 made of the same material if the<br/>mean drift velocity of the electron is:<br/>

Question 18 :
A current of $16 \ A$ is made to pass through a conductor in which the number density of free electrons is $\displaystyle 4\times { 10 }^{ 28 }{ m }^{ -3 }$ and its area of cross section is $\displaystyle { 10 }^{ -5 }{ m }^{ 2 }$. The average drift velocity of free electrons in the conductor is:

Question 19 :
A copper wire of $3\ mm^{2}$ cross sectional area carries a current of $5\ ampere$. The magnitude of the drifty velocity for the electrons in the wire, (Assume copper to be monovalent, $M_{Cu} = 63.5\ kg/k\ mol$ and density of copper $= 8920\ kg/m^{3})$.

Question 20 :
Drift velocity varies with the intensity of electric field as per the relation

Question 21 :
A battery of {tex}24{/tex} cells, each of emf {tex} 1.5 V {/tex} and internal resistance {tex} 2 \Omega {/tex} is to be connected in order to send the maximum current through a {tex}12{/tex} {tex} \Omega {/tex} resistor. The correct arrangement of cells will be

Question 22 :
The equivalent resistance between the points {tex} P {/tex} and {tex} Q {/tex} in the network given here is equal to (given {tex} \left. r = \frac { 3 } { 2 } \Omega \right) {/tex} <br> <img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5db97c3e980e63103bdbebc7">

Question 23 :
When a photon of light collides with a metal surface, possible number of electrons coming out is?

Question 24 :
Estimate the average drift speed of conduction electrons in a copper wire of cross-sectional area $\displaystyle 1.0\times { 10 }^{ -7 }{ m }^{ 2 }$ carrying a current of $1.5\ A$. Assume that each copper atom contributes roughly one conduction electron. The density of copper is $\displaystyle 9.0\times { 10 }^{ 3 }{ kgm }^{- 3 }$ and its atomic mass is $63.5\ amu$.