 # CBSE Class 12 Physics Last 5 + 1 Years’ Short Answer Type Questions

CBSE class 12 Physics last 5 + 1 years’ short answer type questions are available in this article. These questions are helpful in understanding the level of questions which can be asked in CBSE class 12 Physics board exam 2017. CBSE class 12 Physics last 5 + 1 years’ short answer type questions are available in this article.

According to the latest examination pattern, there will be 5 very short answer type questions (or 2 mark questions) will be asked in CBSE class 12 Physics board exam 2017. Before the year 2015, ten very short answer type questions of 2 marks were asked in CBSE class 12th Physics examinations.

CBSE Class 12 Syllabus 2017

In order to understand the level of questions which can be asked in CBSE class 12 Physics exam 2017, students must go through these questions.

The solutions of these questions are available in CBSE Class 12th Solved Previous Years' Papers (Last 5+ 1 years') PCM - eBook

The questions are as follows:

 CBSE Class 12 Physics Board Exam 2016: Short Answer Type Questions (2 Marks) Q. A ray PQ incident normally on the refracting face BA is refracted in the prism BAC made of material of refractive index 1.5. Complete the path of ray through the prism. From which face will the ray emerge? Justify your answer. CBSE Classs 12 Physics Marking Scheme Q. Calculate the de-Broglie wavelength of the electron orbiting in the n = 2 state of hydrogen atom. Q. Define modulation index. Why is it kept low? What is the role of a bandpass filter? Q. A battery of emf 12V and internal resistance 2 Ω is connected to a 4 Ω resistor as shown in the figure. (a) Show that a voltmeter when placed across the cell and across the resistor, in turn, gives the same reading. (b) To record the voltage and the current in the circuit, why is voltmeter placed in parallel and ammeter in series in the circuit? CBSE Class 12 NCERT Solutions Q. Define ionization energy. How would the ionization energy change when electron in hydrogen atom is replaced by a particle of mass 200 times that of the electron but having the same charge? CBSE Class 12 Physics Board Exam 2015: Short Answer Type Questions (2 Marks) Q. Write the important characteristic features by which the interference can be distinguished from the observed diffraction pattern. OR Explain the basic differences between the construction and working of a telescope and a microscope. CBSE Class 12 Question Papers 2016 Q. State Bohr’s postulate of hydrogen atom which successfully explains the emission lines in the spectrum of hydrogen atom. Use Rydberg formula to determine the wavelength of Hα line.[Given: Rydberg constant R = 1.03 × 107 m–1] Q. State the two Kirchhoff’s rules used in electric networks. How are these rules justified? Q. Given the ground state energy E = –13.6 eV and Bohr radius a = 0.53 . Find out how the de Broglie wavelength associated with the electron orbiting in the ground state would change when it jumps into the first excited state. Q. (a) Distinguish between ‘Analog’ and ‘Digital’ forms of communication. (b) Explain briefly two commonly used applications of the ‘Internet’. CBSE Class 12 Chapter Notes CBSE Class 12 Physics Board Exam 2014: Short Answer Type Questions (2 Marks) Q. Using Rutherford model of the atom, derive the expression for the total energy of the electron in hydrogen atom. What is the significance of total negative energy possessed by the electron? OR Using Bohr's postulates of the atomic model derive the expression for radius of nth electron orbit. Hence obtain the expression for Bohr's radius. Q. A parallel plate capacitor of capacitance C is charged to a potential V. It is then connected to another uncharged capacitor having the same capacitance. Find out the ratio of the energy stored in the combined system to that stored initially in the single capacitor. Q. Considering the case of a parallel plate capacitor being charged, show how one is required to generalize Ampere's circuital law to include the term due to displacement current. Q. A cell of emf 'E' and internal resistance 'r' is connected across a variable resistor 'R'. Plot a graph showing variation of terminal voltage 'V' of the cell versus the current 'I'. Using the plot, show how the emf of the cell and its internal resistance can be determined. CBSE Class 12 Sample Papers Q. Explain, with the help of a circuit diagram, the working of a p-n junction diode as a half-wave rectifier. Q. Estimate the average drift speed of conduction electrons in a copper wire of cross-sectional area 1.0 × 10−7 m2 carrying a current of 1.5 A. Assume the density of conduction electrons to be 9 × 1028 m−3. Q. Two monochromatic rays of light are incident normally on the face AB of an isosceles right-angled prism ABC. The refractive indices of the glass prism for the two rays '1' and '2' are respectively 1.35 and 1.45. Trace the path of these rays after entering the prism. Q. Write the functions of the following in communication systems: (i) Transducer (ii) Repeater Q. Show diagrammatically the behaviour of magnetic field lines in the presence of (i) paramagnetic and (ii) diamagnetic substances. How does one explain this distinguishing feature? Q. Draw a circuit diagram of n-p-n transistor amplifier in CE configuration. Under what condition does the transistor act as an amplifier? CBSE Class 12 Physics Board Exam 2013: Short Answer Type Questions (2 Marks) Q. Draw typical output characteristics of n-p-n transistor in CE configuration. Show how these characteristics can be used to determine output resistance. Q. A parallel beam of light of 500nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1m away. It is observed that the first minimum is at a distance of 2.5mm from the centre of the screen. Calculate the width of the slit. Q. A slab of material of dielectric constant K has the same area as that of the plates of a parallel plate capacitor but has the thickness d/2, where d is the separation between the plates. Find out the expression for its capacitance when the slab is inserted between the plates of the capacitor. Q. A capacitor, made of two parallel plates each of plate area A and separation d, is being charged by an external ac source. Show that the displacement current inside the capacitor is the same as the current charging the capacitor. Q. Explain the term ‘drift velocity’ of electrons in a conductor. Hence obtain the expression for the current through a conductor in terms of ‘drift velocity’. OR Describe briefly, with the help of a circuit diagram, how a potentiometer is used to determine the internal resistance of a cell. Q. A convex lens of focal length f1 is kept in contact with a concave lens of focal length f2. Find the focal length of the combination. Q. In the block diagram of a simple modulator for obtaining an AM signal, shown in the figure, identify the boxes A and B. Write their functions. Q. In the circuit shown in the figure, identify the equivalent gate of the circuit and makes its truth table CBSE Class 12 Physics Board Exam 2012: Short Answer Type Questions (2 Marks) Q. A test charge ‘q’ is moved without acceleration from A to C along the path from A to B then from B to C in electric field E as shown in the figure. (i) Calculate the potential difference between A and C. (ii) At which point (of the two) is the electric potential more and why? Q. An electric dipole is held in a uniform electric field. (i) Show that the net force acting on it is zero. (ii)The dipole is aligned parallel to the field. Find the work done in rotating its through the angle of180°. Q. State the underlying principle of a transformer. How is the large scale transmission of electric energy over long distances done with the use of the transformers? Q. A capacitor of capacitance ‘C’ is being charged by connecting it across a dc source along with an ammeter. Will the ammeter show a momentary deflection during the process of charging? If so, how would you explain this momentary deflection and the resulting continuity of current in the circuit? Write the expression for the current inside the capacitor. Q. An object AB is kept in front of concave mirror as shown in the figure. (i) Complete the ray diagram showing the image formation of the object . (ii)How will the position and intensity of the image be affected if the lower half of the mirror's reflecting surface is painted black? Q. Draw a labelled ray diagram of a reflecting telescope. Mention its two advantages over the refracting telescope. Q. Describe briefly with the help of a circuit diagram, how the flow of current carriers in a p-n-p transistor is regulated with emitter-base junction forward biased and base-collector junction reverse biased. Q. In the given block diagram of receiver, identify the boxes labelled as X and Y and write their functions. Q. A light bulb is rated 100 W for 220 V ac supply of 50 Hz. Calculate (i) the resistance of the bulb; (ii) the rms current through the resistor. OR An alternating voltage given by V = 140 sin 314t is connected across a pure resistor of 50 W. Find (i) the frequency of the source. (ii)the rms current through the resistor. Q. A circular coil of N turns and radius R carries I. It is unwound and rewound to make another coil of radius R/2, current I remaining the same. Calculate the ratio of the magnetic moments of the new coil and original coil. CBSE Class 12 Physics Board Exam 2011: Short Answer Type Questions (2 Marks) Q. A thin straight infinitely long conducting wire having charge density λ is enclosed by a cylindrical surface of radius r and length l, its axis coinciding with the length of the wire. Find the expression for the electric flux through the surface of the cylinder? Q. Plot a graph showing the variation of coulomb force (F) versus 1/r2 where r is the distance between the two charges of each pair of charges: (1μC, 2μC) and (2μC, – 3μC). Interpret the graphs obtained? Q. Write the expression for Lorentz magnetic force on a particle of charge 'q' moving with velocity v in a magnetic field B. Show that no work is done by this force on the charged particle. OR A steady current (I1) flows through a long straight wire. Another wire carrying steady current (I2) in the same direction is kept close and parallel to the first wire. Show with the help of a diagram how the magnetic field due to the current I1 exerts a magnetic force on the second wire. Write the expression for this force. Q. What are eddy currents? Write any two applications of eddy currents. Q. What is sky wave communication? Why is this mode of propagation restricted to the frequencies only up to few MHz’s? CBSE Class 12 Video Tutorials Q. In the given circuit, assuming point A to be at zero potential, use Kirchoff’s rules to determine the potential at point B. Q. A parallel plate capacitor is being charged by a time varying current. Explain briefly how Ampere’s circuital law is generalized to incorporate the effect due to the displacement current? Q. Net capacitance of three identical capacitors in series is 1 µF. What will be their net capacitance if connected in parallel? Find the ratio of energy stored in the two configurations if they are both connected to the same source. Q. Using the curve for the binding energy per nucleon as the function of the mass number A, state clearly how the release in energy in the processes of nuclear fission and nuclear fusion can be explained? Q. In the meter bridge experiment, balanced point was observed at J with AJ = l. (a) The values of R and X were doubled and then interchanged. What would be the new position of balance point? (b) If the galvanometer and battery are interchanged at the balance position, how will the balance point get affected?

CBSE Class 12th Solved Previous Years' Papers (Last 5+ 1 years') PCM - eBook