List of top Questions asked in CBSE CLASS XII- 2026

When the forward bias voltage in a semiconductor diode is changed from 0·8 V to 1·0 V, the forward current changes by 2·0 mA. The forward bias resistance of the diode will be :
In which of the following, total internal reflection does not occur ?
The phase difference between the two superimposing waves that give rise to a bright spot in a Young’s double-slit experiment is (\(n\) is an integer) :
A proton and an alpha particle have equal momentum. The ratio of their kinetic energies (\(E_p /E_\alpha\)) and de Broglie wavelengths associated with them (\(\lambda_p /\lambda_\alpha\)) respectively are :
A telescope has an objective lens of focal length 144 cm and an eyepiece of focal length 6·0 cm. The magnifying power and the length of telescope tube will be respectively :
Radiation of wavelength 200 nm is incident on a photosensitive surface of work function 4·2 eV. The kinetic energy of fastest photoelectrons emitted from this surface will be close to :
A particle of mass \(m\) and charge \(q\) starts from rest and moves in an electric field \(\vec{E} = E_0 \hat{i}\). After travelling a distance \(x\) in the field along \(x\)-axis, the kinetic energy of the particle will be :
A thin plano-convex lens and a thin equi-concave lens are kept coaxially in contact as shown in the figure. Assuming both the lenses are made of glass of refractive index \(\mu\), and \(R\) is the radius of curvature of each curved surface, the focal length of the combination is :
A square loop of side 50 cm is placed in a uniform magnetic field of 3·0 T acting perpendicular to the plane of the loop. If the loop is rotated through an angle of \(90^\circ\) in 0·3 s, the value of emf induced in the loop would be :
What is speed? Explain the methods to develop speed in detail.
What do you understand by motivation? Which motivational techniques are used to improve the performance of the players? Explain in detail.
A plane electromagnetic wave travels through a medium and the magnetic field associated with it is given by \[ B = 5 \times 10^{-8} \sin (3 \times 10^{10} t - 150 x) \text{ T} \] where \(x\) is in metres and \(t\) is in seconds. The velocity of the wave is :
Raghav plans to conduct strength and flexibility tests specifically for the lower body, targeting his grandfather's friend. Explain in detail the procedure and scoring system to administer these tests.
Differentiate between Scoliosis and Lordosis deformities. Suggest corrective measures for Knock-knee and Flat foot deformities.
Describe three factors those affect the trajectory of a projectile.
Elucidate three physiological changes those occur due to ageing.
Devise a plan of physical activities in accordance with World Health Organization guidelines for adults aged 65 and above.
Enlist the asanas for obesity. Explain the procedure of any one asana for it.
Prashant began vomiting after lunch at school. He was promptly taken to a nearby doctor, who diagnosed him with food intolerance. Outline three types of food intolerance.
Briefly explain talent selection in the process of talent identification and talent development.
Briefly explain talent transfer in the process of talent identification and talent development.
Compare and contrast the intramural and the extramural tournament.
In the example given below, which of Newton's Laws of Motion will apply? Justify your answer: When a cricket and tennis ball are thrown with the same force, the tennis ball moves with greater acceleration.
Explain the procedure of any one strength test of the SAI Khelo India Fitness Test used for 9 to 18 years class 4 to 12 children.
In the example given below, which of Newton's Laws of Motion will apply? Justify your answer: When a Swimmer pushes the water backwards.