List of practice Questions

A source producing sound of frequency \(990\) Hz and an observer are initially at rest. If both the source and observer start moving simultaneously towards each other with accelerations \(2\ \mathrm{ms^{-2}}\) and \(4\ \mathrm{ms^{-2}}\) respectively, then the frequency of sound heard by the observer at a time \(t=5\) s is \[ (\text{Speed of sound in air}=340\ \mathrm{ms^{-1}}) \]

Select the correct order of steps of plant tissue culture:
A. Explant sterilization
B. Selection of media
C. Excision of regenerated shoots
D. Inoculation of explants
E. Transfer of plantlets to sterilised soil

She was ...... waiting for her mother.

Why could the reforms initiated by Mikhail Gorbachev not save the disintegration of Soviet Union? Explain any two reasons.

Four friends P, Q, R, and S were discussing the examples of genetic disorders. The examples they quoted were as follows:
P. Colour blindness and Malaria
Q. Albinism and Cholera
R. Haemophilia and Colour blindness
S. Haemophilia and Albinism
Who gave the correct examples?

For what value(s) of c, the pair of equations \(x - 2y = 8; 5x - 10y = c\) have infinite solution ?

Choose the word closest in meaning to “innocuous”.

The in-situ stresses are determined by the Flat-jack method by making three slots (P, Q, and R) on the wall (ABCD) of a mine gallery as shown. The in-situ stresses \( \sigma_P \), \( \sigma_Q \), and \( \sigma_R \) are determined at slot-P, slot-Q, and slot-R, respectively. If \( \sigma_P > \sigma_Q \), and \( \sigma_R = 0 \), the shear stress on the wall is

If \( y = \cos^{-1} x \), find \( \frac{d^2y}{dx^2} \) in terms of \( y \).

Two blocks ($P$ and $Q$) with respectively masses $2\text{ kg}$ and $1.5\text{ kg}$ are joined by a massless thread. These blocks are mounted on a frictionless pully which is fixed on the edge of a cube $(S)$, as shown in the figure below. Block $P$ is positioned on the top surface which has no friction and block $Q$ is in contact with side-surface, having coefficient friction $\mu$. The cube $(S)$ moves towards the right with acceleration of $\frac{g}{2}$, where $g$ is gravitational acceleration. During this movement the block $P$ and $Q$ remain stationary. The value of $\mu$ is ______. (take $g = 10\text{ m/s}^2$)

If \(y = f\left(\frac{3 + 2x}{3 - 2x}\right)\), where \(f(x) = \tan(\log x)\), and \(\frac{dy}{dx} = \frac{A}{B + Cx^2} \cdot \sec^2\left(\log \frac{3 + 2x}{3 - 2x}\right)\), then find \(A, B, C\).

On the outline map of India provided: (i) Mark and name the fold mountain range of India.
(ii) Mark with an arrow and name the river also known as the 'Sorrow of Bihar'.
(iii) Shade and label the Gulf of Kutch.
(iv) Mark and label the Karakoram Pass.
(v) Mark and label an offshore oil field of India.
(vi) Shade and label the Laterite soil area in the northeastern part of India.
(vii) Mark and name the shared capital city of Punjab and Haryana.
(viii) Mark and label the Western Ghats.
(ix) Shade and label the river Krishna.
(x) Shade and label an area of dense population.

एक आदर्श गैस A में अणुओं का माध्य मुक्त पथ, एक अन्य आदर्श गैस B में अणुओं के माध्य मुक्त पथ का आधा है। गैस A के गोलाकार अणुओं का व्यास, गैस B के अणुओं के व्यास का दोगुना है। यदि गैसों A और B के संख्या घनत्व क्रमशः \(n_A\) और \(n_B\) हैं, तो सही विकल्प है:

Rohan failed an important exam. Instead of accepting that he didn't prepare well, he insists that the teacher was biased and the exam was unfair. Which defence mechanism is Rohan using?

A, B and C are partners sharing profits in the ratio of \(5 : 3 : 2\). If C retires, the New Profit Sharing Ratio between A and B will be :

Anitha and Sunitha are equal partners. Their Balance Sheet on 31.03.2025 is as under :

a) Assets realised as follows :
Debtors ₹ 30,000 ; Bills Receivable ₹ 12,000 ; Computers ₹ 25,000 ; Machinery ₹ 45,000 ; Land ₹ 85,000 ; and Unrecorded investment ₹ 3,000
b) Liabilities are paid in full.
c) Cost of dissolution amounted to ₹ 6,000.
Prepare :
i) Realisation Account,
ii) Partners' Capital Accounts and
iii) Bank Account.

If \(n\) is an odd natural number and \[ I_n=\int_0^1 e^x(x-1)^n\,dx \] then \( I_n+nI_{n-1} \) is equal to:

An electromagnetic wave of frequency 100 MHz propagates through a medium of conductivity, $\sigma = 10$ mho/m. The ratio of maximum conduction current density to maximum displacement current density is _________.
$\left[ \text{Take } \frac{1}{4\pi\epsilon_0} = 9 \times 10^9 \text{ Nm}^2/\text{C}^2 \right]$

Identify one relief feature found in the grid square 3796.

Arrange the following events in chronological order and choose the correct option: I. Salt Satyagraha
II. Kheda Satyagraha
III. Rowlatt Satyagraha
IV. Ahmedabad Mill Workers Satyagraha

In the image shown below, PQ = QR = QS = 2 units. Also, QT = TS = QU = UR. The points T and U are the centre points of the semicircles. What is the total area of shaded portions in square units?

Assertion (A): A thick cuticle reduces transpiration by acting as a barrier.
Reason (R): Desert plants have large, thin leaves for transpiration.

When an element 'X' reacts with water, it starts floating. Identify the element 'X':

In photoelectric emission, the frequency of incident light is doubled. Kinetic energy of emitted photoelectrons will become: