List of top Questions asked in JEE Main

What is the sum of the infinite series \( S = \sum_{n=0}^{\infty} \frac{1}{3^n} \)?

In a sound wave, the displacement of the air particles follows the equation \( y = A \cos(kx - \omega t) \). What is the wave velocity?

What is the time period of a simple pendulum of length \( L \) and acceleration due to gravity \( g \)?

In a resistive circuit, the power dissipated by a resistor \( R \) when a current \( I \) flows through it is given by \( P = I^2 R \). What happens to the power when the current is doubled?

A block of mass \( m \) is moving with velocity \( v \) on a smooth horizontal surface. If a constant force \( F \) is applied to the block, what is the work done by this force after 5 seconds?

In the context of the photoelectric effect, what is the threshold frequency \( f_0 \) for a metal if the work function is \( \phi = 2 \, \text{eV} \)?

Find the dimensions of \( \frac{B}{\mu_0} \)

For \([ \text{NiCl}_4 ]^{2-}\), what is the charge on the metal and shape of the complex respectively?

Compare boiling point of given solutions:
(i) \( 10^{-4} \) NaCl
(ii) \( 10^{-3} \) NaCl
(iii) \( 10^{-2} \) NaCl
(iv) \( 10^{-4} \) urea

Which of the following is the correct order of acidic strength for the following compounds: HNO\(_3\), HClO\(_4\), and HClO\(_3\)?

What is the hybridization of the central atom in the molecule \( \text{SO}_3 \)?

In an oxidation-reduction reaction, what happens to the oxidation state of the central atom in \( \text{MnO}_4^- \) when it is reduced to \( \text{Mn}^{2+} \)?

In the reaction \( 2\text{H}_2\text{O}_2 \rightarrow 2\text{H}_2\text{O} + \text{O}_2 \), what is the role of potassium iodide (KI) in this reaction?

What is the shape of the \( \text{ClO}_2^- \) ion according to VSEPR theory?

Let {an}ⁿ⁼⁰_∞be a sequence such that a₀=a₁=0 and a_n+2=3a_n+1−2a_n+1,∀ n≥0. Then a₂₅a₂₃−2a₂₅a₂₂−2a₂₃a₂₄+4a₂₂a₂₄is equal to

The sum of the cubes of all the roots of the equation x⁴ – 3x³ –2x² + 3x +1 = 0 is

N>40000, where N is divisible by 5. How many such 5 digit numbers can be formed using 0,1,3,5,7,9 without repetition.

Let $A$ be the area of the region
$\left\{(x, y): y \geq x^2, y \geq(1-x)^2, y \leq 2 x(1-x)\right\}$.
Then $540 A$ is equal to ______.

Match List - I with List - II.

List - I (Pair of Compounds)	List - II (Isomerism)
(A) n-propanol and Isopropanol	(I) Metamerism
(B) Methoxypropane and ethoxyethane	(IV) Functional Isomerism
(C) Propanone and propanal	(III) Position Isomerism
(D) Neopentane and Isopentane	(II) Chain Isomerism

Given below are two statements:
Statement (I): Viscosity of gases is greater than that of liquids.
Statement (II): Surface tension of a liquid decreases due to the presence of insoluble impurities.
In the light of the above statements, choose the most appropriate answer from the options given below:

Why does oxygen show anomalous behavior ?

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Melting point of Boron (2453 K) is unusually high in group 13 elements.
Reason (R): Solid Boron has a very strong crystalline lattice.
In the light of the above statements, choose the most appropriate answer from the options given below:

Give below are two statements:
Statement-I : Noble gases have very high boiling points.
Statement-II: Noble gases are monoatomic gases. They are held together by strong dispersion forces. Because of this they are liquefied at very low temperature. Hence, they have very high boiling points.
In the light of the above statements, choose the correct answer from the options given below.

Evaluate the following statements related to group 14 elements for their correctness.
(A) Covalent radius decreases down the group from C to Pb in a regular manner.
(B) Electronegativity decreases from C to Pb down the group gradually.
(C) Maximum covalence of C is 4 whereas other elements can expand their covalence due to presence of d orbitals.
(D) Heavier elements do not form ppi-ppi bonds.
(E) Carbon can exhibit negative oxidation states.
Choose the correct answer from the options given below:

A train starting from rest first accelerates uniformly up to a speed of 80 km/h for time t, then it moves with a constant speed for time 3t. The average speed of the train for this duration of journey will be (in km/h) :