Physics 12 past paper 2023

Sum of the masses of constituent nucleons as compared to the mass of the resultant nucleus is:

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Show that **electric field** is **potential gradient** ($E = \frac{\Delta V}{d}$).

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Derive an expression for energy stored in a capacitor.

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In the time constant of RC circuit, how much charge is stored, out of maximum charge $q_{o}$?

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What is **"electron volt"**? Show its relationship with joule.

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The full-scale deflection of galvanometer is $10 \text{ mA}$; its resistance is $50 \Omega$. How can it be converted into an ammeter of range $200 \text{ A}$?

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The electric field at a distance of $20 \text{ cm}$ from $4 \mu C$ charge is:

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How can a rheostat be used as a potential divider?

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What is meant by **motional emf**? Also derive an expression for motional emf.

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For a closed circuit:

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A heating coil has a resistance of $10 \Omega$. It is designed to operate on $220 \text{ V}$. What electric energy in joules is supplied to the heater in $20 \text{ seconds}$?

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An A.C circuit consists of a pure resistance of $10 \Omega$ and is connected across an A.C supply of $220 \text{ V}, 100 \text{ Hz}$. Calculate: (i) Current (ii) Power consumed (ii…

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Why is low resistance in an ammeter called **shunt resistance**? Why is this 'shunt' connected in parallel to the galvanometer?

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What is **de Broglie's hypothesis**? Describe an experiment to show that a particle can have wave characteristics.

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If a charge is at rest in a magnetic field, then the magnetic force on charge is:

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Is it possible to accelerate a neutron in a cyclotron (magnetic field)? Justify your answer.

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Find the wavelength associated with an electron in the state $n=3$ of the hydrogen atom.

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A 2 m wire carrying current 5 A is at right angles to a uniform magnetic field of 0.2 Wb/m². The force on the wire will be:

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Briefly explain the need of laminated iron cores in transformers.

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The component in a generator which consumes energy is called:

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In a coil, current changes from $6 \text{ A}$ to $8 \text{ A}$ in $0.05 \text{ s}$. If the average E.M.F is $10 \text{ V}$, then find the coefficient of self-inductance.

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The circuit in which current and voltage are in phase, the power factor is:

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How can radio waves be produced? Describe how information can be transmitted by radio waves.

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An alternating voltage is given by $30 \sin(157t)$, the frequency of alternating voltage is:

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An inductor with an inductance of $100 \mu H$, passes a current of $5 \text{ mA}$ when its terminal potential is $8 \text{ V}$. Calculate the frequency of A.C supply.

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Which of the following is the Young Modulus of steel?

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Highlight the importance of superconductors in MRI machines.

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Differentiate 'elastic deformation' and 'plastic deformation'.

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A potential barrier of $0.7 \text{ V}$ exists across a PN junction made from:

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Under what conditions does a transistor act as an open and a closed switch?

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The minimum energy required by a photon to create an electron-positron pair is:

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Briefly explain how electrons and holes flow across a P-N junction.

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According to de-Broglie equation, **___** has the smallest wavelength associated with it.

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Should the rest mass of photon be zero? Justify your answer.

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If an atom exists in excited state $n = 3$, the number of transitions that take place is:

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Briefly explain the following terms: (a) Unified Mass Scale (b) Mass Defect

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The duration of metastable state is approximately:

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Differentiate between excitation potential and ionization energy.

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The inner shell transitions in heavy elements result into emission of characteristic X-Rays. How do these X-Rays differ from visible light?

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Describe any two basic forces of nature.

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Does fusion reaction release more energy per nucleon than fission reaction? Explain briefly.

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