List of top Questions asked in Joint Entrance Exam

A conducting bar moves on two conducting rails as shown in the figure. A constant magnetic field $ B $ exists into the page. The bar starts to move from the vertex at time $ t = 0 $ with a constant velocity. If the induced EMF is $ E \propto t^n $, then the value of $ n $ is _____.

Concentrated nitric acid is labelled as 75%by mass. The volume in mL of the solution which contains 30 g of nitric acid is: Given: Density of nitric acid solution is 1.25 g/mL.

A physical quantity $ Q $ is related to four observables $ a $, $ b $, $ c $, and $ d $ as follows: \[ Q = \frac{a b^4}{c d^2} \] Where:
- $ a = (60 \pm 3) \, \text{Pa} $,
- $ b = (20 \pm 0.1) \, \text{m} $,
- $ c = (40 \pm 0.2) \, \text{N·s/m}^2 $,
- $ d = (50 \pm 0.1) \, \text{m} $.
Then the percentage error in $ Q $ is:

Let circle $C$ be the image of
$$ x^2 + y^2 - 2x + 4y - 4 = 0 $$
in the line
$$ 2x - 3y + 5 = 0 $$
and $A$ be the point on $C$ such that $OA$ is parallel to the x-axis and $A$ lies on the right-hand side of the centre $O$ of $C$.
If $B(\alpha, \beta)$, with $\beta < 4$, lies on $C$ such that the length of the arc $AB$ is $\frac{1}{6}$ of the perimeter of $C$, then $\beta - \sqrt{3}\alpha$ is equal to:

Assume a living cell with 0.9%($w/w$) of glucose solution (aqueous). This cell is immersed in another solution having equal mole fraction of glucose and water. (Consider the data up to first decimal place only) The cell will:

Given below are two statements:

Statement (I):
are isomeric compounds.

Statement (II):
are functional group isomers.

In the light of the above statements, choose the correct answer from the options given below:

Let $ [x] $ denote the greatest integer function, and let $ m $ and $ n $ respectively be the numbers of the points, where the function $ f(x) = [x] + |x - 2| $, $ -2<x<3 $, is not continuous and not differentiable. Then $ m + n $ is equal to:

The effect of temperature on the spontaneity of reactions are represented as: Which of the following is correct?

The electric field of an electromagnetic wave in free space is \[ \vec{E} = 57 \cos \left[7.5 \times 10^6 t - 5 \times 10^{-3} (3x + 4y)\right] \left( 4\hat{i} - 3\hat{j} \right) \, \text{N/C}. \] The associated magnetic field in Tesla is:

Total number of non-bonded electrons present in $ \text{NO}_2 $; ion based on Lewis theory is:

In the sulphur estimation, 0.20 g of a pure organic compound gave 0.40 g of barium sulphate. The percentage of sulphur in the compound is

In the Claisen-Schmidt reaction to prepare dibenzalacetone from 5.3 g benzaldehyde, a total of 3.51 g of product was obtained. The percentage yield in this reaction was _____.

Isomeric hydrocarbons $ \rightarrow $ negative Baeyer's test (Molecular formula $ \text{C}_9\text{H}_{12} $). The total number of isomers from above with four different non-aliphatic substitution sites is -

Which one of the following, with HBr, will give a phenol?

First ionisation enthalpy values of the first four group 15 elements are given below. Choose the correct value for the element that is a main component of the apatite family:

The type of oxide formed by the element among Li, Na, Be, Mg, B and Al that has the least atomic radius is:

Drug X becomes ineffective after 50% decomposition. The original concentration of drug in a bottle was 16 mg/mL which becomes 4 mg/mL in 12 months. The expiry time of the drug in months is ____ . Assume that the decomposition of the drug follows first order kinetics.

Which one of the following reaction sequences will give an azo dye?

If \[ \text{C(diamond)} \rightarrow \text{C(graphite)} + X \, \text{kj mol}^{-1} \] \[ \text{C(diamond)} + \text{O}_2(g) \rightarrow \text{CO}(g) + Y \, \text{kj mol}^{-1} \] \[ \text{C(graphite)} + \text{O}_2(g) \rightarrow \text{CO}(g) + Z \, \text{kj mol}^{-1} \] At constant temperature. Then:

Total number of sigma ($ \sigma $) and pi ($ \pi $) bonds respectively present in hex-1-en-4-yne are:

Identify the homoleptic complexes with odd number of d-electrons in the central metal:

(A) [FeO₄]²⁻ (B) [Fe(CN)₆]³⁻

(C) [Fe(CN)₅NO]²⁻ (D) [CoCl₄]²⁻

(E) [Co(H₂O)₃F₃]

Choose the correct answer from the options given below :

O$_2$ gas will be evolved as a product of electrolysis of:
(A) an aqueous solution of AgNO3 using silver electrodes.
(B) an aqueous solution of AgNO3 using platinum electrodes.
(C) a dilute solution of H2SO4 using platinum electrodes.
(D) a high concentration solution of H2SO4 using platinum electrodes.
Choose the correct answer from the options given below :

0.1 M solution of KI reacts with excess of $ \text{H}_2\text{SO}_4 $ and KIO$_3$, according to the equation: \[ 5I^- + 6H^+ \rightarrow 3I_2 + 3H_2O \]

Identify the correct statements:

(A) 200 mL KI solution reacts with 0.004 mol of KIO₃
(B) 200 mL KI solution reacts with 0.006 mol of H₂SO₄
(3) 0.5 L KI solution produced 0.005 mol of I₂
(4) Equivalent weight of KIO₃ is equal to Molecular weight / 5

Given below are two statements:
Statement (I): On nitration of m-xylene with $ \text{HNO}_3 $, $ \text{H}_2\text{SO}_4 $, followed by oxidation, 4-nitrobenzene-1, 3-dicarboxylic acid is obtained as the major product.
Statement (II): CH$_3$ group is o/p-directing while NO$_2$ group is m-directing group.
In the light of the above statements, choose the correct answer from the options given below:

Given below are two statements:
Statement (I): NaCl is added to the ice at $ 0^\circ C $, present in the ice cream box to prevent the melting of ice cream.
Statement (II): On addition of NaCl to ice at $ 0^\circ C $, there is a depression in freezing point.
In the light of the above statements, choose the correct answer from the options given below:

List of top Questions asked in Joint Entrance Exam - 2025