List of top Questions asked in JEE Main- 2023

A car is moving with speed of 150km/h and after applying the brake it will move 27m before it stops. If the same car is moving with a speed of one third the reported speed then it will stop after travelling ______m distance.

Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from $n =4$ to $n =2$ of $He ^{+}$spectrum

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

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 $\left( h =6.62 \times 10^{-34} Js \right)$

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 :

The number of integral values of $k$, for which one root of the equation \[2x^2 - 8x + k = 0\] lies in the interval $(1, 2)$ and its other root lies in the interval $(2, 3)$, is:

How many bromo products are formed when ethane is reacted with excess of Br₂ on heating?

The mean and standard deviation of 10 observations are 20 and 8 respectively. Later on, it was observed that one observation was recorded as 50 instead of 40. Then the correct variance is:

Which of the following statements is correct about freons?

Separation between earth and sun is given by 1.5 × 10⁶ km. Time period of another planet is 2.83 year. Find distance of another planet from sun?

Match List I with List II

Choose the correct answer from the options given below:

If $\int \limits_0^\pi \frac{5^{\cos x}\left(1+\cos x \cos 3 x+\cos ^2 x+\cos ^3 x \cos 3 x\right) d x}{1+5^{\cos x}}=\frac{ k \pi}{16}$, then $k$ is equal to

The resistance of a wire is $5 \Omega$. It's new resistance in ohm if stretched to 5 times of it's original length will be:

How many moles of Ba₃(PO₄)₂ will be formed by the reaction of 5 moles of BaCl₂ and 3 moles of Na₃(PO₄).

For which of the following aqueous ion, spin only magnetic moment is 3.87 BM?

During the qualitative analysis of $SO _3^2$ using dilute $H _2 SO _4, SO _2$ gas is evolved which turns $K _2 Cr _2 O _7$ solution (acidified with dilute $H _2 SO _4$ ) :

The minimum number of elements that must be added to the relation $R=\{(a, b),(b, c),(b, d)\}$ on the set $\{a, b, c, d\}$ so that it is an equivalence relation, is _______

The dissociation constant of acetic acid is $x \times 10^{-5}$ When $25 \,mL$ of $0.2 \,M \,CH _3 COONa$ solution is mixed with $25 \,mL$ of $0.02\, M \,CH _3 COOH$ solution, the $pH$ of the resultant solution is found to be equal to 5. The value of $x$ is ___

If $a_1,a_2,.......a_n$ are in arithmetic progression with common difference $d>n$, then find limit $\lim_{n \to \infty}\sqrt{\frac{d}{n}}(\frac{1}{\sqrt{a_1}+\sqrt{a_2}})+\frac{1}{\sqrt{a_2}+\sqrt{a_3}}+.......+\frac{1}{\sqrt{a_n}+\sqrt{a_{n-1}}})$ is____.

Element not present in Nessler’s reagent is

The solubility product of BaSO₄ is $1 \times 10^{-10}$ at 298 K. The solubility of BaSO₄ in 0.1 M K₂SO₄(aq) is $x \times 10^{-9}$ g L⁻¹. Calculate the value of $x$.

Let $A = \{x \in \mathbb{R}: |x+3| + |x+4| \le 3\}$,} \[ B = \left\{ x \in \mathbb{R} : 3 \cdot \sum_{r=1}^{\infty} \frac{3^{x-3}}{10^r} < 3^{-3x} \right\}, \] where $[x]$ denotes the greatest integer function. Then,

A person has been using spectacles of power $-1.0$ dioptre for distant vision and a separate reading glass of power $2.0$ dioptres What is the least distance of distinct vision for this person :

An object of mass $8 kg$ is hanging from one end of a uniform rod CD of mass $2 kg$ and length $1 m$ pivoted at its end $C$ on a vertical wall as shown in figure It is supported by a cable $AB$ such that the system is in equilibrium The tension in the cable is : (Take $g =10 m / s ^2$ )

The frequency ($ \nu $) of an oscillating liquid drop may depend upon the radius ($ r $) of the drop, density ($ \rho $) of the liquid, and the surface tension ($ s $) of the liquid as: \[ \nu = k r^a \rho^b s^c \]
The values of $ a $, $ b $, and $ c $ respectively are:

List I		List II
A		I	Fittig reaction
B		II	Wurtz Fittig reaction
C		III	Finkelstein reaction
D	\(C_{2}H_{5}CI + NaI \rightarrow C_{2}H_{5}I + NaCl\)	IV	Sandmeyer reaction