List of top Questions asked in COMEDK UGET

A student measures the terminal potential difference \(V\) of a cell (emf \(\varepsilon\) and internal resistance \(r\)) as a function of current \(I\) flowing through it, and draws \(V\) versus \(I\) graph. The slope and intercept of the graph respectively are
Three identical conducting balls A, B and C, each of mass \(m\), are thrown upward at an angle \(\theta\) to the horizontal with an initial speed \(v\) in a region of space that has a uniform electric field \(E\) downward along with the gravitational field \(g\). A is positively charged, B is uncharged and C is negatively charged. Rank the ranges \(R\) of these three balls in increasing order.
A symmetric double convex lens is cut into two equal parts by a plane perpendicular to the principal axis. If the power of the original lens is \(4D\), the difference between the powers of the original lens and the cut lens is
An ideal inductor is connected across a capacitor. Oscillations of energy \(K\) are set up in the circuit. The capacitor plates are slowly drawn apart such that the frequency of oscillations is quadrupled. The work done in the process is
In a single slit Fraunhofer diffraction pattern obtained at normal incidence, at the angular position of the second diffraction minimum the phase difference (in radian) between the waves from the opposite edges of the slit is
Which of the following is not a characteristic of diamagnetism?
According to Bohr's theory of hydrogen atom, the speed of the electron, its energy and radius of its orbit vary with the principal quantum number \( n \), respectively as
Two light rays A and B travel from a medium into air at angles of incidence 15 degrees and 42 degrees respectively. In the medium, light travels 3 cm in 0.2 ns. Will there be total internal reflection? If so, which ray?
An electric field \( E = 3x^2 \, i \, \text{N C}^{-1} \) exists in a certain region of space. The potential difference between the origin and at \( x = 4 \, m \), \( V_0 - V_4 \) is
Two statements, One Assertion [A] and the other Reason [R] are given. Identify the correct option.
Assertion [A]: The decreasing order of the acidic character of the following is \(B>D>A>C\).
Reason [R]: Fluorine has larger \(-I\) effect than Cl and Br.
A current loop consists of two identical semicircular parts each of radius \(2R\), one lying in the \(x-y\) plane and the other in \(x-z\) plane. If the current in the loop is \(I\), the resultant magnetic field due to two semicircular parts at their common centre is
The nuclear forces
(a) are central forces, independent of the spin of the nucleons.
(b) have a short-range dominant over a distance of about a few fermi
(c) are stronger being hundred times stronger than that of electromagnetic forces.
(d) are independent of the nuclear charge.
Which of the above is not true?
A particle of mass \( M \) at rest decays into masses \( m_1 \) and \( m_2 \) with non-zero velocities. The ratio of de Broglie wavelengths \( \lambda_1 \) and \( \lambda_2 \) of the particles is
The conductivity of \(0.01\ M\) solution of \(CH_3COOH\) at 298 K is \(1.65 \times 10^{-4}\ S cm^{-1}\). What is the \(pK_a\) value of the acid if \(\lambda^0(H^+)\) and \(\lambda^0(CH_3COO^-)\) are \(349.1\ Scm^2 mol^{-1}\) and \(40.9\ Scm^2 mol^{-1}\) respectively?
\(X \rightarrow 2Y\) is a first order reaction where \(1.0 \, \text{mol/L}\) of the reactant yields \(0.4 \, \text{mol/L}\) of \(Y\) in 200 minutes. Calculate the half-life period of the reaction in minutes.
Match the reactions of glucose given in Column I with the major product formed in the reaction as in Column II.
Two statements, one Assertion (A) and the other Reason (R) are given. Choose the correct option.
Assertion: 2-aminoethanoic acid and p-aminobenzene sulphonic acid can exist as Zwitter ions while p-aminobenzoic acid cannot.
Reason: When the acid group is a relatively strong proton donor and the \(-NH_2\) group is sufficiently basic it can accept a \(H^+\) ion from the acid group to form the dipolar ion.
The following results were obtained during study of the reaction \(2NO(g) + Cl_2(g) \rightarrow 2NOCl(g)\). Determine the value of \([X]\) in mol/L.
A certain gas absorbs photon of wavelength \(4.0 \times 10^{-7} \, m\) and emits radiation at two wavelengths. If one of the emissions occurs at \(7.5 \times 10^{-7} \, m\), what is the wavelength at which the second emission occurs?
Identify X, the final product formed when 2 moles of ethanal undergoes the following series of reactions with reagents (i) to (iv).
\[ \mathrm{CH_3CHO \xrightarrow[(ii)\ HCl]{(i)\ dil.\ NaOH} \xrightarrow{(iii)\ NaBH_4} \xrightarrow{(iv)\ Cr_2O_7^{2-}/H^+}{} [X]} \]
What is the spin only magnetic moment of the metal ion in P and the oxidation number of Sulphur in the oxidised product Z?
Two statements, one Assertion (A) and the other Reason (R) are given. Choose the correct option.
Assertion (A): Maltose, a disaccharide, is a reducing sugar and is obtained by the partial hydrolysis of starch in presence of the enzyme diastase.
Reason (R): Hydrolysis of one mole of Maltose gives one mole each of \( \alpha\text{-D-Glucose} \) and \( \beta\text{-D-Fructose} \).
Which one of the following options represents the decreasing order of oxidation number of the central atom in:
\[ \mathrm{Cr_2O_7^{2-}, \; CrO_2^{-}, \; MnO_4^{-}, \; BrO_3^{-}} \]
Cyclohexanol undergoes a series of reactions as given. Identify compound (iv).
\[ C_6H_{11}OH + CrO_3 \rightarrow (i) + C_6H_5MgI \rightarrow (ii) + \text{dil. }HCl \rightarrow (iii) + \text{Conc. }H_3PO_4 \rightarrow (iv) \]
Match the structures in Column I with their correct IUPAC names given in Column II.