List of top Physics Questions asked in UP Board XII

How much energy is released in mass defect of 1 amu?
Draw the energy level diagram for hydrogen atom. Show the transitions of Lyman, Balmer, Paschen, Brackett and Pfund series in the diagram. In which region do these spectrum lie?
What is LED? Explain its principle, construction and working.
As the temperature of a metal and of a semiconductor is increased, the:
The equivalent resistance of the network shown in figure between A and B is:
What is the meaning of wavefront? Explain the laws of reflection by explaining Huygens' principle of wavefront.
What do you understand by electromagnetic induction? State Faraday’s laws regarding electromagnetic induction.
The equation \( E = pc \), where \( E \), \( p \), and \( c \) represent energy, momentum, and velocity of light, is valid:
Obtain the formula for refractive index of material of prism in terms of angle of minimum deviation and angle of prism.
Derive the formula for the capacitance of a parallel plate capacitor, partially filled with a dielectric.
Explain both the laws of Kirchhoff of electrical circuits.
What is the meaning of matter-wave of Louis de Broglie? Deduce the relation for wavelength of de Broglie in terms of kinetic energy.
What is a transistor? By drawing the circuit diagram of common emitter configuration, plot the output characteristics.
The energy of an electron of excited hydrogen atom is -3.4 eV. Determine the angular momentum of the electron.
Define the formula for the resonant frequency in a series L-C-R alternating current circuit.
Explain Bohr's model of the atom.
The magnifying power of a telescope is 9. When it is adjusted for parallel rays, the distance between the eye lens and objective is 20 cm. Determine the focal lengths of both the lenses.
Equiconcave lens of crown glass has to be made. How much radii of the surfaces of the lens should be kept so that its power would be -2.5 D? The refractive index of crown glass is 1.65.
On suspending a magnet at 30° with the magnetic meridian, it makes an angle of 45° with the horizontal. What will be the actual angle of dip?
What are meant by ohmic and non-ohmic resistances? Draw the graph between voltage and current for a non-ohmic circuit and define dynamic resistance.
What is a NOR gate? Draw its logic symbol and obtain the truth table.
The equations of current and voltage in a circuit are as follows: \[ i = 3.5 \sin\left(628t + \frac{\pi}{6}\right) \, \text{ampere} \] \[ v = 28 \sin\left(628t - \frac{\pi}{6}\right) \, \text{volt} \] Find:
(i) \text{Root mean square value of current}, (ii) \text{Time period}, (iii) \text{Phase difference between current and voltage.}
Classify nuclei on the basis of atomic number and mass number and define them.
Write four main properties of γ-rays. Whose wavelength is larger among γ-rays and ultraviolet rays?
What will be the effect on focal length and nature of convex lens of refractive index \( n = \frac{3}{2} \) dipped in a liquid of refractive index \( n = \frac{3}{2} \)?