List of top Questions asked in UP Board XII

As compared to \(^{12}_6C\) atom, how many extra protons and neutrons does the \(^{14}_6C\) atom have?
How much energy is released in mass defect of 1 amu?
The electric field of intensity \( \vec{E} = (3 \hat{i} + 4 \hat{j}) \, \text{N/C} \) passes through the plane of area \( \vec{A} = (10 \hat{i}) \, \text{m}^2 \). Find the electric flux.
What do you understand by electromagnetic induction? State Faraday’s laws regarding electromagnetic induction.
What is the meaning of wavefront? Explain the laws of reflection by explaining Huygens' principle of wavefront.
What is LED? Explain its principle, construction and working.
The equation \( E = pc \), where \( E \), \( p \), and \( c \) represent energy, momentum, and velocity of light, is valid:
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:
Obtain the formula for refractive index of material of prism in terms of angle of minimum deviation and angle of prism.
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.
Derive the formula for the capacitance of a parallel plate capacitor, partially filled with a dielectric.
What is a transistor? By drawing the circuit diagram of common emitter configuration, plot the output characteristics.
Define the formula for the resonant frequency in a series L-C-R alternating current circuit.
Explain Bohr's model of the atom.
The energy of an electron of excited hydrogen atom is -3.4 eV. Determine the angular momentum of the electron.
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.
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.
Classify nuclei on the basis of atomic number and mass number and define them.
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.}
Write four main properties of γ-rays. Whose wavelength is larger among γ-rays and ultraviolet rays?
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?
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.