List of top Questions asked in CBSE CLASS XII- 2025

A charged particle is moving in a circular path with velocity \( V \) in a uniform magnetic field \( \vec{B} \). It is made to pass through a sheet of lead and as a consequence, it looses one half of its kinetic energy without change in its direction. How will (1) the radius of its path change? (2) its time period of revolution change?
A cell of emf \( E \) and internal resistance \( r \) is connected across a resistor of variable resistance \( R \). Show graphically the variation of
(a) the terminal voltage across the cell,
(b) the current supplied by the cell,
with \( R \) as it is increased from 0 to the maximum value.
A conductor of length \( l \) is connected across an ideal cell of emf \( E \). Keeping the cell connected, the length of the conductor is increased to \( 2l \) by gradually stretching it. If \( R \) and \( R' \) are the initial and final values of resistance, and \( v_d \) and \( v'_d \) are the initial and final values of drift velocity, find the relation between (i) \( R' \) and \( R \) and (ii) \( v'_d \) and \( v_d \).
Ajay Ltd. forfeited 100 shares of Rs 10 each for non-payment of first call of Rs 1 per share and second and final call of Rs 3 per share. The minimum price per share at which these shares can be reissued will be:

Assertion : In Bohr model of hydrogen atom, the angular momentum of an electron in \( n \)th orbit is proportional to the square root of its orbit radius \( r_n \)

Reason (R): According to Bohr model, electron can jump to its nearest orbits only.

Assertion (A): The deflection in a galvanometer is directly proportional to the current passing through it. 

Reason (R): The coil of a galvanometer is suspended in a uniform radial magnetic field.

Four point charges \( Q \) each, are held at the four corners of a square of side \( l \). The amount of work done in bringing a charge \( Q \) from infinity to the centre of the square will be:
The focal length of a concave mirror in air is \( f \). When the mirror is immersed in a liquid of refractive index \( \frac{3}{5} \), its focal length will become:
A coil of an AC generator, having 100 turns and area 0.1 m² each, rotates at half a rotation per second in a magnetic field of 0.02 T. The maximum emf generated in the coil is:
Choose the correct option to fill the blank:
By 2050, the world population is estimated to live in urban areas is ______.
Identify the main characteristics of quaternary activity from the following:
“Some wastelands are rendered unfit for agriculture by human activities.” Choose the correct option related to the statement:
(i) Shifting cultivation area
(ii) Coastal plains
(iii) Degraded pastures
(iv) Bhabar areas
Choose the correctly matched pair of areas and their characteristics from the following:
The exported items by a port is first brought from different countries. This port is known as ______.
Identify the unit to measure sound from the following:
Arrange the following airports of Asia from west to east as per their locations and choose the correct option:
(i) Beijing
(ii) Tokyo
(iii) Aden
(iv) Mumbai
Identify the main objective of Gas Authority of India Limited (GAIL) from the following:
Identify the district of first phase of construction of Rajasthan canal.
Two statements are given below. They are Assertion (A) and Reason (R). Read both the statements carefully and choose the correct option:
Assertion (A): All manufacturing industries are associated with raw materials.
Reason (R): Resources are essential for human survival.
Arrange the following oil refineries of India from south to north direction as per their locations and choose the correct option:
(i) Mumbai
(ii) Kochi
(iii) Kayali
(iv) Mangaluru
Read the following facts about ‘Swachh Bharat Mission’ carefully and choose the correct option:
(i) It is a part of urban renewable mission.
(ii) It is launched by Government of India.
(iii) It is associated with improving greenery in urban areas.
(iv) It is aimed to improve quality of life in urban slums.
Two statements are given below. They are Assertion (A) and Reason (R). Read both the statements carefully and choose the correct option:
Assertion (A): Water transport plays an important role in the international trade of India.
Reason (R): The east coast of India has more ports than its west coast.
Which of the following statements are correct related to mining? Choose the correct option:
(i) In ancient times minerals were used to make tools and weapons.
(ii) All developed countries are extracting more minerals for their development.
(iii) The actual development of mining began with the industrial revolution.
(iv) There are many stages in the discovery of minerals.
Giri and Shyam were partners in a firm sharing profits and losses in the ratio of 3 : 2. Their capitals were ₹1,60,000 and ₹1,00,000 respectively. Hema was admitted for $\dfrac{1}{5}$ share in the profits of the firm. Hema brought ₹1,50,000 as her capital. The goodwill of the firm on Hema’s admission was:
When applications for more shares of a company are received than the number of shares offered to the public for subscription, it is known as: