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Explore Class 12 Physics past and model questions by chapter, year, marks and question type.
478 questions found
Compare β-particles and γ-rays in terms of their mass, charge, ionizing power and penetrating power.
For the digital circuit given below, write the truth table showing the outputs Y₁, Y₂ for all possible inputs at A and B.
A plane transmission grating has 5000 lines per cm and the second order spectral line is diffracted through 30°. Calculate the wavelength of light used.
Define decay constant.
The isotope carbon-14 has half life 5700 years. If the sample contains 10²² carbon-14 nuclei, find its activity.
Show that the speed of an object undergoing simple harmonic motion is given by the expression
where the symbols carry standard meanings.
He could have used an ordinary voltmeter to measure the emf of the test cell directly. The student, however, argues that the above instrument is more precise than an ordinary voltmeter. Justify his logic.
The figure shows the Lyman series of energy transmission in the hydrogen atom. Calculate the frequency of a photon emitted by an electron jumping from the second excited state to the ground level.
Prove that this force will make the rock vibrate with simple harmonic motion.
Establish a relation between surface tension and surface energy of a liquid.
Sketch the symbol of a p-n junction diode and indicate the polarity of its ends.
He obtained the balance point for distance 37.5cm using a standard cell of emf 1.50V. And for the test cell, the balance distance AB was 25.0 cm. Calculate the emf of the test cell.
State and explain what change, if any, occurs to the maximum speed of the emitted electrons when the intensity of the ultraviolet radiation is increased.
Show that the maximum speed of the electrons emitted from the surface of the aluminium is $8.6 \times 10^{5}\,\text{m s}^{-1}$
Two identical copper balls are dropped from the same height as shown in the figure. Ball P passes through a region of uniform horizontal magnetic filed of flux density B. Explain why ball P takes longer than ball Q to reach the ground.
State what the symbols ε and dϕ/dt represent in the equation.
Explain the significance of the negative sign
Copy the outline of a diode bridge rectifier and complete it by adding diodes in the gaps.
Define “harmonics‟ in music
Calculate the frequency of a monotonous sound produced by a 30 cm long flute open at both ends and being played in the first harmonic. [Velocity of sound in air= 330 ms-1]