List of top Questions asked in JEE Main

For a moving coil galvanometer, the deflection in the coil is $005$ rad when a current of $10 \,mA$ is field is $0,01 \,T$ and the number of turns in the coil is $200$ , the area of each tum (in $cm ^2$ ) is :
Statement I: When a Si sample is doped with Boron, it becomes P type and when doped by Arsenic it becomes N-type semi conductor such that P-type has excess holes and N-type has excess electrons.
Statement II: When such P-type and N-type semi-conductors, are fused to make a junction, a current will automatically flow which can be detected with an externally connected ammeter.
In the light of above statements, choose the most appropriate answer from the options given below
Two objects are projected with same velocity ' $u$ ' however at different angles $\propto$ and $\beta$ with the horizontal If $\alpha+\beta=90^{\circ}$, the ratio of horizontal range of the first object to the 2nd object will be :
The graph between two temperature scales $P$ and $Q$ is shown in the figure Between upper fixed point and lower fixed point there are 150 equal divisions of scale $P$ and 100 divisions on scale $Q$ : The relationship for conversion between the two scales is given by:-
Every planet revolves around the sun in an elliptical orbit:-
A. The force acting on a planet is inversely proportional to square of distance from sun
B. Force acting on planet is inversely proportional to product of the masses of the planet and the sun
C. The Centripetal force acting on the planet is directed away from the sun
D. The square of time period of revolution of planet around sun is directly proportional to cube of semi-major axis of elliptical orbit
Choose the correct answer from the options given below:
Match List I with List II
List IList II
A.TroposphereI.Approximate 65-75 km over Earth’s surface
B.E- Part of StratosphereII.Approximate 300 km over Earth’s surface
C.F2- Part of ThermosphereIII.Approximate 10 km over Earth’s surface
D.D- Part of StratosphereIV.Approximate 100 km over Earth’s surface
Choose the correct answer from the options given below:
The light rays from an object have been reflected towards an observer from a standard flat mirror, the image observed by the observer are:- 
A. Real 
B. Erect 
C. Smaller in size then object 
D. Laterally inverted 
Choose the most appropriate answer from the options given below:
A body of mass is taken from earth surface to the height $h$ equal to twice the radius of earth $\left(R_e\right)$ the inerease in potential energy will be:( $g$ = acceleration due to gravity on the surface of Earth)
Match List I with List II
 List I List II
A.Young's Modulus (Y)I.[M L-1 T-1 ]
B.Co-efficient of Viscosity (η)II.[M L2 T-1 ]
C.Planck's Constant (h)III.[M L-1 T-2 ]
D.Work Function (ϕ)IV.[M L2 T-2 ]
Choose the correct answer from the options given below:
The energy levels of an atom is shown in figure:

 Which one of these transitions will result in the emission of a photon of wavelength $1241\, nm$ ? Given $\left( h =6.62 \times 10^{-34} Js \right)$
Given below are two statements:
Statement I : In froth floatation method a rotating paddle agitates the mixture to drive air out of it.
Statement II : Iron pyrites are generally avoided for extraction of iron due to environmental reasons.
In the light of the above statements, choose the correct answer from the options given below:
A. Ammonium salts produce haze in atmosphere 
B. Ozone gets produced when atmospheric oxygen reacts with chlorine radicals
C. Polychlorinated biphenyls act as cleansing solvents 
D. 'Blue baby' syndrome occurs due to the presence of excess of sulphate ions in water 
Choose the correct answer from the options given below:
Given below are two statements, one is labelled as Assertion $A$ and the other is labelled as Reason $R$
Assertion A: Carbon forms two important oxides - $CO$ and $CO _2 .CO$ is neutral whereas $CO _2$ is acidic in nature
Reason R : $CO _2$ can combine with water in a limited way to form carbonic acid, while $CO$ is sparingly soluble in water
In the light of the above statements, choose the most appropriate answer from the options given below
Match List I with List II :
List-I Coordination entityList-II Wavelength of light absorbed in nm
A.\([CoCl(NH_3​)_5​]^{2+}\)I.310
B.\([Co(NH_3​)_6​]^{3+}\)II.475
C.\([Co(CN)_6​]^{3−}\)III.535
D.\([Cu(H_2​O)_4​]^{2+}\)IV.600
Choose the correct answer from the options given below :
What is the mass ratio of ethylene glycol \((C _2H _6O_2\), molar mass \(62\ g/mol)\) required for making \(500\ g\) of \(0.25\) molal aqueous solution and \(250\ ml\) of \(0.25\) molal aqueous solution?
Which one among the following metals is the weakest reducing agent?

A bowl filled with very hot soup cools from $98^{\circ} C$ to $86^{\circ} C$ in 2 minutes when the room temperature is $22^{\circ} C$. How long it will take to cool from $75^{\circ} C$ to $69^{\circ} C$ ?

A solenoid of $1200$ tums is wound uniformly in a single layer on a glass tube $2\, m$ long and $02\, m$ in diameter The magnetic intensity at the center of the solenoid when a current of $2 A$ flows through it is:

Compound A reacts with $NH _4 Cl$ and forms a compound B.

Compound B reacts with $H _2 O$ and excess of $CO _2$ to form compound $C$ which on passing through or reaction with saturated $NaCl$ solution forms sodium hydrogen carbonate Compound $A , B$ and $C$, are respectively.

The correct order in aqueous medium of basic strength in case of methyl substituted amines is :
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason $R$:
Assertion A: Acetal / Ketal is stable in basic medium
Reason R: The high leaving tendency of alkoxide ion gives the stability to acetal ketal in basic medium
In the light of the above statements, choose the correct answer from the options given below :
Which one of the following reactions does not occur during extraction of copper?

A cubic solid is made up of two elements $X$ and $Y$ Atoms of $X$ are present on every alternate corner and one at the enter of cube $Y$ is at $\frac{1}{3} td$ of the total faces The empirical formula of the compound is

The mean and variance of the marks obtained by the students in a test are 10 and 4 respectively Later, the marks of one of the students is increased from 8 to 12 If the new mean of the marks is $10.2$, then their new variance is equal to :

If $a_r$ is the coefficient of $x^{10-r}$ in the Binomial expansion of $(1+x)^{10}$, then $\displaystyle\sum_{r=1}^{10} r^3\left(\frac{a_r}{a_{r-1}}\right)^2$ is equal to