List of top Physics Questions asked in JEE Main

In an experiment to find emf of a cell using potentiometer, the length of null point for a cell of emf $15 \,V$ is found to be $60 \,cm$ If this cell is replaced by another cell of emf $E$, the length-of null point increases by $40 \,cm$ The value of $E$ is $\frac{x}{10} V$ The value of $x$ is _______

As shown in the figure, a current of $2 A$ flowing in an equilateral triangle of side $4 \sqrt{3} cm$ The magnetic field at the centroid $O$ of the triangle is

 (Neglect the effect of earth's magnetic field)

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$
Assertion (A): The nuclear density of nuclides ${ }_5^{10} B ,{ }_3^6 Li ,{ }_{26}^{56} Fe ,{ }_{10}^{20} Ne$ and ${ }_{83}^{209} Bi$ can be arranged as $\rho_{ Bi }^N>\rho_{ Fe }^N>\rho_{ Ne }^N>\rho_{ B }^N>\rho_{ Li }^N$.
Reason R: The radius $R$ of nucleus is related to its mass number $A$ as $R=R_0 A^{1 / 3}$, where $R_0$ is a constant.
In the light of the above statements, choose the correct answer from the options given below

The average kinetic energy of a molecule of the gas is

The mass of proton, neutron and helium nucleus are respectively $10073\, u$, $10087\, u$ and $40015\, u$ The binding energy of helium nucleus is:

A current carrying rectangular loop $P Q R S$ is made of uniform wire The length $P R=Q S=5 \,cm$ and $P Q=R S=100\, cm$ If ammeter current reading changes from $I$ to $2 I$, the ratio of magnetic forces per unit length on the wire $P Q$ due to wire $R S$ in the two cases respectively $\left(f_{P Q}^I: f_{P Q}^{2 I}\right)$ is:

The equivalent resistance between $A$ and $B$ of the network shown in figure:

A vehicle travels $4 \, km$ with speed of $3\, km / h$ and another $4 \, km$ with speed of $5\, km / h$, then it's average speed is

A steel wire with mass per unit length $70 \times 10^{-3} kg\, m ^{-1}$ is under tension of $70 \,N$.
The speed of transverse waves in the wire will be:

Which of the following frequencies does not belong to FM broadcast?

If a solid sphere of mass $5 kg$ and a disc of mass $4 kg$ have the same radius Then the ratio of moment of inertia of the disc about a tangent in its plane to the moment of inertia of the sphere about its tangent will be $\frac{x}{7}$ The the value of $x$ is ___

Find the magnetic field at the point $P$ in figure. The curved portion is a semicircle connected to two long straight wires

A series LCR circuit is connected to an $AC$ source of $220 V , 50 Hz$ The circuit contains a resistance $R =80 \Omega$, an inductor of inductive reactance $X _{ L }=70 \Omega$, and a capacitor of capacitive reactance $X _{ C }=130 \Omega$ The power factor of circuit is $\frac{x}{10}$ The value of $x$ is :

Two cells are connected between points $A$ and $B$ as shown Cell 1 has emf of $12 V$ and internal resistance of $3 \Omega$ Cell 2 has emf of $6 V$ and internal resistance of $6 \Omega$ An external resistor $R$ of $4 \Omega$ is connected across $A$ and $B$ The current flowing through $R$ will be ___A

A body of mass $1 kg$ collides head on elastically with a stationary body of mass $3 kg$ After collision, the smaller body reverses its direction of motion and moves with a speed of $2 m / s$ The initial speed of the smaller body before collision is ___ $ms ^{-1}$

Two long parallel wires carrying currents $8 A$ and $15 A$ in opposite directions are placed at a distance of $7 cm$ from each other A point $P$ is at equidistant from both the wires such that the lines joining the point $P$ to the wires are perpendicular to each other The magnitude of magnetic field at $P$ is___$\times 10^{-6} T$(Given : $\sqrt{2}=1.4$ )

A train blowing a whistle of frequency $320 Hz$ approaches an observer standing on the platform at a speed of $66 m / s$ .The frequency observed by the observer will be ____ Hz,
(Given speed of sound $=330 ms ^{-}$ 1)

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason $R$
Assertion A: Efficiency of a reversible heat engine will be highest at $-273^{\circ} C$ temperature of cold reservoir
Reason R: The efficiency of Carnot's engine depends not only on temperature of cold reservoir but it depends on the temperature of hot reservoir too and is given as $n =\left(1-\frac{T_2}{T_1}\right)$
In the light of the above statements, choose the correct answer from the options given below

Match List I with List II: 

List I		List II
A.	Attenuation	I.	Combination of a receiver and transmitter
B.	Transducer	II.	Process of retrieval of information from the carrier wave at received
C.	Demodulation	III.	Converts one form of energy into another
D.	Repeater	IV.	Loss of strength of a signal while propagating through a medium

Choose the correct answer from the options given below :

Match List I with List II:

List I		List II
A	AC generator	i	Presence of both L and C
B	Transformer	ii	Electromagnetic Induction
C	Resonance phenomenon to occur	iii	Quality factor
D	Sharpness of resonance	iv	Mutual Induction

Choose the correct answer from the options given below:

Match List I with List II: 

List - I		List - II
A.	Torque	I.	kg m-1 s-2
B.	Energy Density	II.	kg ms-1
C.	Pressure gradient	III.	kg m-2 s-2
D.	Impulse	IV.	kg m2 s-2

Choose the correct answer from the options given below : 

Given below are two statements :
Statement I: Stopping potential in photoelectric effect does not depend on the power of the light source
Statement II: For a given metal, the maximum kinetic energy of the photoelectron depends on the wavelength of the incident light.
In the light of above statements, choose the most appropriate answer from the options given below

The distance travelled by a particle is related to time $t$ as $x=4 t^2$ The velocity of the particle at $t-5 s$ is:-