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All Physics 12 papers

Class 12 · Past paper

Physics 12 past paper 2023

41 published questions in this index. The full practice view lets you work through them and track your own attempts.

15 MCQs26 written questionsPractise this paper

Question index

1
Sum of the masses of constituent nucleons as compared to the mass of the resultant nucleus is:
MCQ1 marksannual
1
Show that **electric field** is **potential gradient** ($E = \frac{\Delta V}{d}$).
Part B3 marksannual
1
Derive an expression for energy stored in a capacitor.
Part C7 marksannual
2
In the time constant of RC circuit, how much charge is stored, out of maximum charge $q_{o}$?

This is a skimmable index, not a replacement for the study surface. Open the practice view to answer questions and use the linked study material.

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2

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

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2

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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3

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

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3

How can a rheostat be used as a potential divider?

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3

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

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4

For a closed circuit:

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4

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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4

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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5

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

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5

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

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6

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

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6

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

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6

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

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7

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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7

Briefly explain the need of laminated iron cores in transformers.

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8

The component in a generator which consumes energy is called:

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8

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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9

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

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9

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

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10

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

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10

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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11

Which of the following is the Young Modulus of steel?

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11

Highlight the importance of superconductors in MRI machines.

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12

Differentiate 'elastic deformation' and 'plastic deformation'.

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13

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

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13

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

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14

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

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14

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

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15

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

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15

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

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16

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

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16

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

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17

The duration of metastable state is approximately:

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17

Differentiate between excitation potential and ionization energy.

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18

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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19

Describe any two basic forces of nature.

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20

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

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Physics 12 Past Paper 2023 | Notely