Question 1 :
There are two charges +1 <font face="Symbol">&micro;</font>C and +5 <font face="Symbol">&micro;</font>C. The ratio of the forces acting on them will be

Question 2 :
Half part of ring is uniformly positively charged and other half is uniformly negatively charged. Ring is in equilibrium in uniform electric field as shown and free to rotate about an axis passing through its centre and perpendicular to plane. The equilibrium is <br> <img style='object-fit:contain' style="max-width:240px;" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5f16c33df1a5a149feab9a64"/>

Question 3 :
On moving a charge of 20 coulomb by {tex} 2 \mathrm { cm } , 2 \mathrm { J } {/tex} of work is done, then the potential difference between the points is

Question 4 :
Consider two concentric metal spheres. The outer sphere is given a charge <em>Q</em> > 0, then <br> <img style='object-fit:contain' style="max-width:240px;" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5f16c3281da6d070c2abfa14"/>

Question 5 :
Two equal point charges are fixed at <em>x</em> = -<em>a</em> and <em>x</em> = + <em>a</em> on the <em>x</em>-axis. Another point charge <em>Q</em> is placed at the origin. The change in the electrical potential energy of system, when it is displaced by a small distance <em>x</em> along the <em>x</em>-axis, is approximately proportional to

Question 6 :
A solid hemispherical uniform charged body having charge <em>Q</em> is kept symmetrically along the <em>y</em>-axis as shown in figure. The electric potential at a distance <em>d</em> from the origin along the <em>x</em>-axis at point <em>P</em> will be <img style='object-fit:contain' style="max-width:240px;" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5f16c3084bec8070e4e15115"/>

Question 7 :
A current <em>I</em> is passing through a wire having two sections <em>P</em> and <em>Q</em> of uniform diameters <em>d</em> and <em>d</em>/2 respectively. If the mean drift velocity of electrons at <em>P</em> and <em>Q</em> is denoted by <em>v_p</em> and <em>v_Q</em> respectively, then

Question 8 :
A capacitance is formed by two identical metal plates. The plates are given charges $Q_1$ and $Q_2 (Q_2 &lt; Q_1) $ . If capacitance of the capacitor is $C,$ what is the p.d. between the plates?

Question 9 :
A bar magnet when placed at an angle of 30&deg; to the direction of magnetic field induction of 5 &times; 10^--4 T, experiences a moment of couple 25 &times; 10^-6 N-m. If the length of the magnet is 5 cm, its pole strength is-

Question 10 :
Force between two identical bar magnets whose centres are {tex} r {/tex} metre apart is {tex} 4.8 \mathrm { N } , {/tex} when their axes are in the same line. If separation is increased to {tex} 2 r {/tex}, the force between them is reduced to

Question 11 :
Two straight horizontal parallel wires are carrying the same current in the same direction, {tex} d {/tex} is the distance between the wires. You are provided with a small freely suspended magnetic needle. At which of the following positions will the orientation of the needle be independent of the magnitude of the current in the wires

Question 12 :
In the figure shown a coil of single turn is wound on a sphere of radius <em>R</em> and mass <em>m</em>. The plane of the coil is parallel to the inclined plane and lies in the equatorial plane of the sphere. Current in the coil is <em>i</em>. The value of <em>B</em> if the sphere is in equilibrium is <img style='object-fit:contain' style="max-width:240px;" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5f16c59a4bec8070e4e1523c"/>

Question 13 :
<font>A compass needle placed at a distance r from a short magnet in tanA position shows a deflection of 60</font>^{<font>0</font>}<font>. If the distance is increased to r(3)</font>^{<font>1/3</font>}<font>, then the deflection of the compass needle is -</font></p>

Question 14 :
The e.m.f. of a standard cell balances across {tex} 150 \mathrm { cm } {/tex} length of a wire of potentiometer. When a resistance of {tex} 2 \Omega {/tex} is connected as a shunt with the cell, the balance point is obtained at {tex} 100 \mathrm { cm } . {/tex} The internal resistance of the cell is

Question 16 :
For a metallic wire, the ratio {tex} V / i\ ( V = {/tex} the applied potential difference, {tex} i = {/tex} current flowing) is

Question 17 :
The resistance of a wire is 10Ω. Its length is increased by 10% by stretching. The new resistance will now be nearly

Question 18 :
When a photon of light collides with a metal surface, possible number of electrons coming out is?

Question 19 :
An e.m.f. of {tex}12{/tex} volt is produced in a coil when the current in it changes at the rate of {tex}45{/tex} amp/minute. The inductance of the coil is

Question 20 :
A current of 1 A through a coil of inductance of 200 mH is increasing at a rate of 0.5 A s-1. The energy stored in the inductor per second is

Question 21 :
In the adjoining figure the impedance of the circuit will be<br><img style='object-fit:contain' src="https://data-screenshots.sgp1.digitaloceanspaces.com/5db829e893abcb1b68814396.jpg" />

Question 22 :
Two capacitors of capacitance <em>C</em>₁and <em>C</em>₂ are charged to a potential difference of <em>V</em>₁ and <em>V</em>₂ respectively and are connected to an inductor of inductance <em>L</em> as shown in the figure. Initially key <em>k</em> is open. Now key <em>k</em> is closed and current in the circuit starts increasing. When current in the circuit is maximum <img style='object-fit:contain' style="max-width:240px;" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5f16c7a6f1a5a149feab9bf7"/>

Question 23 :
The self inductance of a long solenoid cannot be increased by

Question 24 :
Loop {tex} A {/tex} of radius {tex} r ( r << R ) {/tex} moves towards a constant current carrying loop {tex} B {/tex} with a constant velocity {tex} v {/tex} in such a way that their planes are parallel and coaxial. The distance between the loops when the induced EMF in {tex} \operatorname { loop } A {/tex} is maximum is<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5d5b94092184804a12322152" /><br>

Question 25 :
The physical quantity which is measured in the unit of Wb A^-1 is