Physics | NEB Class 12 Question Paper 2080-2023 | Old Course | Code-210 - PDF

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NEB Class 12 Exam Question Papers COLLECTION 2080-2023.

Repair and Maintenance of Electrical Equipments | Question Paper 2080-2023 of Class 12 NEB (Technical Stream) (Sub. Code: 664) (Old Course) | PDF Download.

History | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 256) (Old Course) | PDF Download.

Culture | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 266) (Old Course) | PDF Download.

Elements of Finance-II | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 606) (Old Course) | PDF Download.

Child Development and Learning | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 902) (Old Course) | PDF Download.

Gender Studies | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 1241) (New Course) | PDF Download.

Human Value Education | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 1321) (New Course) | PDF Download.

Psychology | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 1201) (New Course) | PDF Download.

History | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 1221'A') (New Course) | PDF Download.

Rural Development | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 1061) (New Course) | PDF Download.

Hospitality Management | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 1261'A') (New Course) | PDF Download.

Vegetable and Medicinal Plant Production | Question Paper 2080-2023 of Class 12 NEB (Technical Stream) (Sub. Code: 9251) (New Course) | PDF Download.

Switch Gear and Protection | Question Paper 2080-2023 of Class 12 NEB (Technical Stream) (Sub. Code: 9261) (New Course) | PDF Download.

Power Transmission and Distribution | Question Paper 2080-2023 of Class 12 NEB (Technical Stream) (Sub. Code: 9291) (New Course) | PDF Download.

Travel and Tourism | Question Paper 2080-2023 of Class 12 NEB (Old Course) (Sub. Code: 274) | PDF Download.

Industrial Crop Production | Question Paper 2080-2023 of Class 12 NEB (Technical Stream) (Sub. Code: 9221) (New Course) | PDF Download.

Non-ruminant Production and Management | Question Paper 2080-2023 of Class 12 NEB (Technical Stream) (Sub. Code: 9181) (New Course) | PDF Download.

General Surgery and Radiology | Question Paper 2080-2023 of Class 12 NEB (Technical Stream) (Sub. Code: 9211) (New Course) | PDF Download.

Sociology | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 272) (Old Course) | PDF Download.

Political Science | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 258) (Old Course) | PDF Download.

Maintenance and Rehabilitation of Structure | Question Paper 2080-2023 of Class 12 NEB 2080-2023 (Sub. Code: 660) (Old Course) | PDF Download.

Web Development and Database | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 656) (Old Course) | PDF Download.

Mechanics of Structure | Question Paper 2080-2023 of Class 12 NEB (Technical Stream) (Sub. Code: 9301) (New Course) | PDF Download.

Visual Programming | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 9341) (New Course) | PDF Download.

Software Engineering and Project Management | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 9371) (New Course) | PDF Download.

Social Studies And Life Skill Education (Technical) | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 9011) (New Course) | PDF Download.

Social Studies And Life Skill Education | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 0061 'H') (New Course) | PDF Download.

Physics | Question Paper 2080-2023 of Class 12 NEB (Old Course) (Sub. Code: 210) | PDF Download.

Physics | Question Paper 2080-2023 of Class 12 NEB (Technical Stream) (Sub. Code: 9131) (New Course) | PDF Download.

Optional English | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 3341) (New Course) | PDF Download.

Nepalese Legal System | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 1101) (New Course) | PDF Download.

Mathematics | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 0081 'H') (New Course) | PDF Download.

Marketing | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 910) (Old Course) | PDF Download.

Instructional Pedagogy and Evaluation | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 1181) (New Course) | PDF Download.

Instructional Evaluation | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 918) (Old Course) | PDF Download.

Hotel Management | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 270) (Old Course) | PDF Download.

General Law | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 296) (Old Course) | PDF Download.

Construction Management | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 9331) (New Course) | PDF Download.

Compulsory Nepali | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 0021 'B') (New Course) | PDF Download.

Compulsory English | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 0041D) (New Course) | PDF Download.

Business Studies | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 628) (Old Course) | PDF Download.

Business Mathematics | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 908) (Old Course) | PDF Download.

Biology | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 9101) (New Course) | PDF Download.

Accounting | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 1041'Q') (New Course) | PDF Download.

Compulsory English | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 0041'G') (New Course) | PDF Download.

Compulsory English | Question Paper 2080-2023 of Class 12 NEB (Sub. Code: 004) (Old Course) | PDF Download.

Physics (General Stream) | Question Paper 2080-2023 of Class 12 NEB (New Course) | PDF Download.

Attempt all questions.

Group 'A'

1. Answer any four questions in brief: [4×2=8]

a. A voltammeter measures current more accurately than an ammeter, why ?
b. Does the thermoelectric effect obey the law of conservation of energy ? Explain.
c. Steel is used in making permanent magnets where as soft iron is preferred for making the core of transformer. Why ?
d. The element of a heater is very hot while the wires carrying current are not. Why ?
e. How will an electron move in a homogenous magnetic field if the velocity of the electron at the initial moment forms an angle ‘θ ’ with the force lines of the field ?
f. Why is choke coil preferable to resistor ?

2. Answer, in brief, any four questions: [4×2=8]

a. Beams of electrons and protons having the same initial K.E. enter normally into an electric field, which beam will be more curved ? Justify.
b. “Production of X-rays is the inverse phenomenon of photoelectric effect”. Justify it.
c. What is nanotechnology ? Explain.
d. Why is the mass of a nucleus slightly less than the mass of constituent nucleons ?
e. What do you mean by energy crisis ?
f. State Hubble's law and write the significance of Hubble's constant.

3. Answer, in brief, any one question: [2]

a. If you are walking on the moon surface, can you hear the cracking sound behind you ? Explain.
b. What is the threshold of hearing ? Define one bel.

4. Answer, in brief, any one question : [2]

a. Explain with proper sketch, the differences between wave fronts and wavelets.
b. What is polarizing angle ? Does it depend on the wavelength of light used ?
Group 'B'

5. Answer any three questions: [3×4=12]

a. What is the principle of a potentiometer ? Explain how can you measure the internal resistance of a cell by using potentiometer ?
b. State and explain Biot-Savart’s law and use it to find magnetic field at the centre of circular coil carrying current.
c. What is Seebeck effect ? How does the thermo emf vary with the increase in temperature of hot junction, keeping cold junction at 0° c ? Explain.
d. Derive the condition for resonant frequency of series LCR alternating current circuit.

6. Answer any three questions: [3×4=12]

a. Describe Millikan's experiment to determine the value of Planck's constant. Explain, how Einstein's photoelectric equation is verified from this experiment.
b. What is rectification ? How can you construct a full wave rectifier using two semiconductor diodes ? Explain their working.
c. State Bohr’s postulates. Derive an expression for the radius of nth orbit of H-atom.
d. State the laws of radioactive disintegration. Derive relation between half life and decay constant.

7. Answer any one question: [4]

a. Discuss Newton's formula for the velocity of sound in a gas medium with Laplace's correction.
b. Describe an experiment with necessary theory by which the speed of sound in air may be determined by using resonance air column method.

8. Answer any one question: [4]

a. Describe Michelson’s method to measure the velocity of light.
b. Describe the diffraction of light at a single slit and find the condition for secondary maxima and minima.

Group 'C'

9. Answer any two numerical questions: [2×4=8]

a. Using Kirchhoff ’s rules in the Circuit, Find the current flowing through 2 resistor
b. A silver wire has 1x1030 free electrons per cubic meter, a cross sectional area of 2mm2 and carries a
current of 5A. Calculate the force acting on each electron if the wire is now placed in a magnetic field of flux density 0.15T which is perpendicular to the wire.
c. The magnetic flux passing perpendicular to the plane of a coil is given by  = 4t2+5t+2, where  is in Weber and t is in seconds. Calculate the magnitude of instantaneous emf induced in the coil when t=3sec.

10. Answer any two questions: [2×4=8]

a. A beam of electrons, moving with velocity of 107m/s, enters midway between two horizontal parallel plates in the direction parallel to the plates which are 5cm long and 2cm apart and have a p.d. of V volts
between them. Calculate V if the beam is deflected so that it just grazes the edge of the plate. (Assume e/m =1.76×1011c/kg)
b. Calculate the wavelength of an electron which has been accelerated through a potential difference of 200V. [Take mass of the electron as 9.1 x 10-31 kg and Planck's constant as 6.6 x 10-34 JS.]
c. The energy liberated in the fission of single uranium-235 atom is 3.2×10-19J. Calculate the power production corresponding to the fission of 1g of uranium per day. Assume Avogadro constant as 6.02×1023 mole-1.

11. A train is approaching a cliff at 20m/s. The driver sounds a whistle of frequency 800Hz. What will be the frequency of echo as heard by the driver ? Velocity of sound in air is 350m/s. [4]

12. The distance between two coherent sources in Young's double slit experiment is 0.3mm and the interference pattern is observed on a screen 60cm from the sources. If the wavelength of light used is 6x10-7m, calculate the distance of the third dark fringe form the central bright fringe. [3]