List of top Questions asked in JEE Main

Which of the following compound is used as the antacid?

Let S = {1, 2, 3, 4, 5}
if f : S → P(S), where P(S) is power set of S. Then number of one-one functions f can be made is

A straight line cuts off the intercepts OA = a and OB = b on the positive directions of the x-axis and y-axis, respectively. If the perpendicular from the origin O to this line makes an angle of \(\frac{\pi}{6}\) with the positive direction of the y-axis and the area of △OAB is \(\frac{98\sqrt{3}}{3},\) then a² − b² is equal to:

If [t] denotes the greatest integer \(≤ 1\), then the value of \(3\frac{(e - 1)^2}{e}\) is:

At \(300 K\) the rms speed of oxygen molecules is \(\sqrt {\frac {\alpha+5}{\alpha}}\) times to that of its average speed in the gas. Then, the value of \(\alpha\) will be
(used \(\pi=\frac {22}{7}\))

The time taken by an object to slide down 45° rough inclined plane is n times as it takes to slide down a perfectly smooth 45° incline plane. The coefficient of kinetic friction between the object and the incline plane is:

The ratio of de-Broglie wavelength of an \(\alpha\) particle and a proton accelerated from rest by the same potential is \(\frac {1}{\sqrt 𝑚}\) , the value of \(m\) is-

A fully loaded boeing aircraft has a mass of $5.4×10^5 $ kg. Its total wing area is $500 m^2$. It is in level flight with a speed of 1080 km/h. If the density of air 𝜌 is $1.2 kg m^{−3}$, the fractional increase in the speed of the air on the upper surface of the wing relative to the lower surface in percentage will be. ($𝑔=10 m/s^2$)

Substance A has atomic mass number 16 and half-life of 1 day. Another substance 𝐵 has atomic mass number 32 and half life of $\frac1{ 2}$ day. If both 𝐴 and 𝐵 simultaneously start undergo radio activity at the same time with initial mass 320 g each, how many total atoms of A and B combined would be left after 2 days.

Given below are two statements: 
Statement I: Electromagnetic waves are not deflected by electric and magnetic field.
Statement II: The amplitude of electric field and the magnetic field in electromagnetic waves are related to each other as \(E_0 = \sqrt{\frac{\mu_0}{E_0}}B_0\).  
In the light of the above statements, choose the correct answer from the options given below:

The electric current in a circular coil of four turns produces a magnetic induction 32 T at its centre. The coil is unwound and is rewound into a circular coil of single turn, the magnetic induction at the centre of the coil by the same current will be :

For the given logic gates combination, the correct truth table will be

The modulation index for an A.M. wave having maximum and minimum peak-to-peak voltages of 14 mV and 6 mV respectively is:

The time period of a satellite of earth is 24 hours. If the separation between the earth and the satellite is decreased to one fourth of the previous value, then its new time period will become.

With the help of potentiometer, we can determine the value of emf of a given cell. The sensitivity of the potentiometer is
(A) directly proportional to the length of the potentiometer wire
(B) directly proportional to the potential gradient of the wire 
(C) inversely proportional to the potential gradient of the wire 
(D) inversely proportional to the length of the potentiometer wire
Choose the correct option for the above statements:

For the given figures, choose the correct options:

The equation of a circle is given by $𝑥^2+𝑦^2=𝑎^2$, where 𝑎 is the radius. If the equation is modified to change the origin other than (0,0) then. find out the correct dimensions of A and B in a new equation : $(𝑥−𝐴𝑡)^2+(𝑦−𝑡 𝐵 )^2 =𝑎^2$. The dimensions of 𝑡 is given as $[T^{−1}]$.

A scientist is observing a bacteria through a compound microscope. For better analysis and to improve its resolving power he should. (Select the best option)

A force acts for 20 s on a body of mass 20 kg, starting from rest, after which the force ceases and then body describes 50 m in the next 10 s. The value of force will be:

Identify the correct statements from the following:
A. Work done by a man in lifting a bucket out of a well by means of a rope tied to the bucket is negative.
B. Work done by gravitational force in lifting a bucket out of a well by a rope tied to the bucket is negative.  
C. Work done by friction on a body sliding down an inclined plane is positive.  
D. Work done by an applied force on a body moving on a rough horizontal plane with uniform velocity in zero.  
E. Work done by the air resistance on an oscillating pendulum in negative.  
Choose the correct answer from the options given below:

An object moves at a constant speed along a circular path in a horizontal plane with center at the origin. When the object is at =+2 m, its velocity is $−4\hat{j}m/s$. The object's velocity (v) and acceleration (𝑎) at 𝑥=−2 m will be

An indicator ' X ' is used for studying the effect of variation in concentration of iodide : on the rate of reaction of iodide ion with $H_2O_2 $ at room temp. The indicator ' X ' forms blue colored complex with compound ' A ' present in the solution. The indicator ' X ' and compound 'A' respectively are