 # Rajasthan Board Class 12 Physics Important Questions

Class 12 is a crucial phase in the lives of students, and Physics is a significant part of the Science stream. Hence, students have to pay great attention to their Rajasthan Board Class 12 Physics. Cracking the subject can be challenging as it covers a lot of complex formulas and derivations. A student who aims to ace the subject will have to master all its concepts and topics very thoroughly. Apart from studying from the textbooks and other study materials, students can also access the Rajasthan Board Class 12 Physics Important Questions and solve them for extra practice. It will also help them to self-assess their knowledge gap more effectively.

These questions have been compiled after careful deliberation of the RBSE Class 12 previous year question papers and sample papers to comprehend the types of questions that are being asked in the board exams. Students can click on the link given to access the PDF format of the RBSE Class 12 Physics Important Questions.

1) Write resistance of an ideal voltmeter and an ideal ammeter.

2) Write 2 properties of Magnetic Lines of Force.

3) Write the working principle of an optical fibre.

4) Define Superconductivity.

5) Draw hysteresis curve (B-H curve) for a ferromagnetic substance.

6) Find the de-Broglie wavelength related to an electron accelerated by 104 volt.

7) Define Curie temperature in magnetism.

8) A charged particle oscillates about its equilibrium position with a frequency of 100MHz. What is the frequency of electromagnetic waves produced by the oscillator?

9) A light bulb is rated at 100W for a 220 V supply. Find the peak voltage of the source.

10) In the figure, resistivities of two conductors of the same material are ρ1 Ω- m and ρ2 Ω- m respectively. Write the value of the ratio of p1 and p2. 11) Define binding energy per nucleon and draw a graph of it with mass number.

12) a) Write the definition of Curie temperature for ferromagnetic substances.

b) Obtain an expression for the magnetic moment of an orbital electron.

13) Draw a labelled diagram of an alternating current generator. Determine the induced electromotive force by the rotation of the coil in it.

14) The length of the side of a square loop is 4m. This loop is placed in a uniform magnetic field of 2.5T. Outside the loop, the magnetic field is zero and it is coming outside from magnetic field perpendicularly with velocity 2m/s. Find the value of induced emf in the loop after one second.

15) Write the name of any four waves (radiations) produced in the electromagnetic spectrum.

16) What is logic gates? Write two names of universal logic gates.

17) What is the displacement current? Obtain an expression of displacement current for a charged capacitor. Write Ampere- Maxwell’s law.

18) Write the method to determine the value of an unknown resistance by meter bridge and derive the necessary formula. Draw the circuit diagram.

(b) Write Kirchhoff’s junction rule.

In the given diagram write the value of current I. 20) A ray of light is incident at Brewster’s angle on the surface of a transparent medium. Deduce Brewster’s law by using Snell’s law.

21) Draw the circuit diagram of a practical arrangement to study the characteristics PNP transistor in common emitter configuration. Sketch typical output characteristics curves and explain the calculation of current gain from these curves.

22) State Bio-Savart Law. Using this law, find an expression for the magnetic field at a point on the axis of a current-carrying circular coil.

23) (a) What does it mean by the magnifying power of a Microscope?

(b) An object is placed at 20cm from a convex lens. If 3 times magnified real image is formed by the lens then find the focal length of the lens.

24) What does it mean by mass defect? Establish a relationship between mass defect and nuclear binding energy. And hence write the expression for binding energy per nucleon.

25) Write the name of device “X” in the following given diagram. Explain its working making its circuit diagram. 26) Determine the force acting between two parallel current-carrying conductor wires. Write a theoretical definition of ampere on this basis.

27) Write Gauss’s Law. Determine the electric field at the points which are situated outside and inside of a uniformly charged thin spherical shell. Draw necessary diagrams of Gaussian surfaces.

28) Match the frequency: 29) Define the following :

(a) Total internal reflection

(b) Diffraction of light

(c) Refraction of light.

30) Define a common emitter output characteristic for a transistor.

Draw a circuit diagram for studying the characteristics of an n-p-n transistor in common emitter configuration. Among emitter, base and collector regions of a transistor which one is (a) largest in size and (b) most heavily doped?

31) Write the principle of a capacitor. Derive an expression for the capacitance of a parallel plate capacitor, partially filled with dielectric. Draw the necessary diagram.

32) What is meant by diffraction? Differentiate between diffraction of light and sound waves. Draw the intensity distribution curve in frounhofer diffraction due to a single slit. Explain to maximum intensity in this diffraction.

33) Write one merit and one de-merit of alternating current in comparison of direct current. Obtain an expression for the following in a pure inductive alternating current circuit-

(i) Instantaneous value of current

(ii)Reactance of circuit

(iii) Peak value of current

Draw curve for power in a pure inductive circuit.

34) Write definitions of the plane of vibration and plane of polarisation. Explain the working process to obtain plane polarised light by Nicol prism. Draw the necessary diagram.

35) Describe the construction and the working of Van de graff generator making the labelled diagram.

36) What is a polaroid? Write any two uses of it. How will you identify the polarised light, the partially polarised light and the unpolarised light?

37) Describe the construction of a compound microscope. Derive an expression for its total magnification. Draw a ray diagram for the formation of an image by a compound microscope.

38) What is rectification? Draw the circuit diagram of the half-wave rectifier and explain its working. Show the input ac voltage and output voltage waveforms from the rectifier circuit.

39) Write the working of the cyclotron in brief. Draw a schematic sketch of the cyclotron showing path of accelerated charged particles ( ions) in both Dees.

Derive the following parameters of cyclotron :

(a) Cyclotron frequency and

(b) The kinetic energy of ions in a cyclotron.

40) Define interference of light waves.

41) Draw a diagram of Young’s double silt experiment to produce an interference fringe pattern. Derive an expression of fringe width for bright fringes.

42) Write any two of Maxwell’s Equations.

43) Obtain an expression for magnetic field due to infinitely long straight current carrying conductor by using the Amperes law.

44) Write Rutherford-Soddy law of radioactive decay and derive related equations. Draw the exponential decay curve of a radioactive substance. Write ratio of half life and mean life of a radioactive substance.

45) Calculate de Broglie wavelength of a wave associated with an electron, which is accelerated through a potential difference of 100 V.