List of practice Questions

A point source \(S\) emits unpolarized light uniformly in all directions. At two points A and B, the ratio \(r = I_A/I_B\) of the intensities of light is \(2\). If a set of two polaroids having 45° angle between their pass-axes is placed just before point B, then the new value of r will be ____
A source (S) of sound has frequency\( 240 Hz\). When the observer (O) and the source move towards each other at a speed \(v\) with respect to the ground (as shown in Case 1 in the figure), the observer measures the frequency of the sound to be \(288 Hz\). However, when the observer and the source move away from each other at the same speed v with respect to the ground (as shown in Case 2 in the figure), the observer measures the frequency of sound to be \(n\) Hz. The value of \(n\) is _____.
Alternative_text
Two large, identical water tanks, 1 and 2, kept on the top of a building of height H, are filled with water up to height ℎ in each tank. Both the tanks contain an identical hole of small radius on their sides, close to their bottom. A pipe of the same internal radius as that of the hole is connected to tank 2, and the pipe ends at the ground level. When the water flows from the tanks 1 and 2 through the holes, the times taken to empty the tanks are t1 and t2, respectively. If \(H = ( \frac{16}{ 9} ) ℎ\), then the ratio t1/t2 is ___
Consider the following volume−temperature (V−T) diagram for the expansion of 5 moles of an ideal monoatomic gas.
volume−temperature (V−T) diagram for the expansion of 5 moles of an ideal monoatomic gas.
Considering only P-V work is involved, the total change in enthalpy (in Joule) for the transformation of state in the sequence X→Y→Z is ______.
[Use the given data: Molar heat capacity of the gas for the given temperature range, CV,m = 12 J K−1mol−1 and gas constant, R=8.3 JK−1 mol−1]
Consider the following reaction,
\(2H_2(g) + 2NO(g) \rightarrow N_2(g) + 2H_2O(g)\)
which follows the mechanism given below:
\(2NO(g)\underset{k_{-1}}{\stackrel{k_1}{\rightleftharpoons}} N_2O_2(g)\) (fast equilibrium)
\(N_2O_2(g)+H_2(g) \xrightarrow[]{K_2}N_2O(g)+H_2O\)  (slow reaction)
\(N_2O(g)+H_2(g) \xrightarrow[]{K_3}N_2(g)+H_2O\)  (fast reaction)
The order of the reaction is________
Complete reaction of acetaldehyde with excess formaldehyde, upon heating with conc. NaOH solution, gives P and Q. Compound P does not give Tollens' test, whereas Q on acidification gives positive Tollens' test. Treatment of P with excess cyclohexanone in the presence of catalytic amount of p-toluenesulfonic acid (PTSA) gives product R.
Sum of the number of methylene groups (-CH2-) and oxygen atoms in R is _______
Among V(CO)6, Cr(CO)5, Cu(CO)3, Mn(CO)5, Fe(CO)5, [Co(CO)3]3-, [Cr(CO)4]4-, and Ir(CO)3, the total number of species isoelectronic with Ni(CO)4 is _________.
[Given, atomic number: V = 23, Cr=24, Mn 25, Fe 26, Co 27, Ni 28, Cu = 29, Ir = 77]
In the following reaction sequence, the major product P is formed.

Glycerol reacts completely with excess P in the presence of an acid catalyst to form Q. Reaction of Q with excess NaOH followed by the treatment with CaCl2 yields Ca-soap R, quantitatively. Starting with one mole of Q, the amount of R produced in gram is ______.
[Given, atomic weight: H = 1, C = 12, N = 14, O = 16, Na = 23, Cl = 35, Ca = 40]
Among the following complexes, the total number of diamagnetic species is ______.
[Mn(NH3)6]3+, [MnCl6]3−, [FeF6]3−, [CoF6]3−, [Fe(NH3)6]3+, and [Co(en)3]3+
[Given, atomic number: Mn = 25, Fe = 26, Co = 27;
en = H2NCH2CH2NH2]
A thin uniform rod of length L and certain mass is kept on a frictionless horizontal table with a massless string of length L fixed to one end (top view is shown in the figure). The other end of the string is pivoted to a point O. If a horizontal impulse P is imparted to the rod at a distance x = L/n from the mid-point of the rod (see figure), then the rod and string revolve together around the point O, with the rod remaining aligned with the string. In such a case, the value of n is _____.
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Zitkala-Sa says, “Eating by formula wasn’t the hardest trial in that first day.” What does she mean by ‘Eating by formula’? (Memories of Childhood)
Consider the line $L$ passing through the points $(1, 2, 3)$ and $(2, 3, 5)$. The distance of the point $$ \left( \frac{11}{3}, \frac{11}{3}, \frac{19}{3} \right) $$ from the line $L$ along the line $$ \frac{3x - 11}{2} = \frac{3y - 11}{1} = \frac{3z - 19}{2} $$ is equal to: 
Two long insulated straight wires carrying currents of \( 3A \) and \( 5A \) are arranged in the XY plane as shown in the figure. Find the magnitude and direction of the net magnetic fields at points \( P_1(2m, 2m) \) and \( P_2(-1m, 1m) \). 
Two long insulated straight wires carrying currents
Why does Derry not like being with people? (On The Face Of It)
Number of metal ions characterized by flame test among the following is _______.
$\text{Sr}^{2+}, \text{Ba}^{2+}, \text{Ca}^{2+}, \text{Cu}^{2+}, \text{Zn}^{2+}, \text{Co}^{2+}, \text{Fe}^{2+}$
Describe any five steps taken to save fresh water from industrial pollution.
In the poems ‘Ozymandias’ by Percy Bysshe Shelley and ‘Not Marble, Nor the Gilded Monuments’ by William Shakespeare, the concept of Time is explored, but each poet treats it in a distinct manner. Elucidate.
In the following pair of compounds, which compound undergoes an $\text{S}_{N}$2 reaction faster and why?
compound undergoes an SN2
The magnifying power of an astronomical telescope is 24. In normal adjustment, the distance between its two lenses is 150 cm. Find the focal length of the objective lens.
If \[ \left( \frac{1}{\alpha + 1} + \frac{1}{\alpha + 2} + \dots + \frac{1}{\alpha + 1012} \right) - \left( \frac{1}{2 \cdot 1} + \frac{1}{4 \cdot 3} + \frac{1}{6 \cdot 5} + \dots + \frac{1}{2024 \cdot 2023} \right) \]
“Between the sixth and the fourth centuries BCE, Magadha became the most powerful Mahajanapada.” Explain the statement with examples.
The deflection in a moving coil galvanometer falls from 25 divisions to 5 divisions when a shunt of \( 24 \, \Omega \) is applied. The resistance of the galvanometer coil will be:
Two beams, A and B whose photon energies are $3.3 \, \text{eV$ and $11.3 \, \text{eV}$ respectively, illuminate a metallic surface (work function $2.3 \, \text{eV}$) successively. The ratio of maximum speed of electrons emitted due to beam A to that due to beam B is:}
The diffraction pattern of a light of wavelength 400 nm diffracting from a slit of width 0.2 mm is focused on the focal plane of a convex lens of focal length 100 cm. The width of the 1st secondary maxima will be :
If an iron (III) complex with the formula \[\left[ \text{Fe}(\text{NH}_3)_x (\text{CN})_y \right]^-\]has no electron in its \( e_g \) orbital, then the value of \( x + y \) is: