Engineering Physics II - 2nd Semester Question Papers(Diploma in All Engineering)

Program: Engineering ALL  Full Marks: 60

Year/Part: I/II (2021)   Pass Marks: 24

Subject: Engineering Physics II   Time: 3 hrs.

Candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicate full marks.

           Group 'A'

Attempt any FOUR questions.          [4×6=24]

1.Define equipotential surfaces. Derive an expression for electric potential at a point due to an electric charge.

2.State Biot-Savart's law. Use this law to find the magnetic field at a point on the axis of current carrying circular coil.

3.State Bohr's postulates of hydrogen atom. Derive an expression for the energy of electron in the nth orbit of hydrogen atom.

4.Define beat and beat frequency. Derive an expression for beat frequency.

5.State Stoke's law. Derive an expression for coefficient of viscosity of liquid for a spherical body falling inside the liquid. 

6.What is specific charge of an electron? Explain with necessary theory, the J-J Thomson's experiment to determine specific charge of electron.

           Group 'B'

Attempt any FOUR questions.         [4×3=12]

7.Define capacitance of a capacitor. Derive equivalent capacitance when three capacitors are connected in parallel.

8.How will you convert galvanometer into ammeter?

9.Discuss the various modes of vibration in closed organ pipe.

10.Explain the motion of electron inside the electric field.

11.What is P-N junction diode? Explain the use of P-N diode as half wave rectifier.

12.Define polarization of light. State and prove Brewster's law.

          Group 'C'

Attempt any SIX questions.              [6×4=24]

13. The half-life of 92U238 is 4.5×109 years. Calculate the activity of 1 gm sample of 92U238.

14 Two parallel resistors 60 and 82 are connected with 42 resistor in series. The connection is supplied to a battery of emf 24 V. If a voltmeter is connected across 42 resistor, find the reading shown by voltmeter.

15. Α 502 resistor, 2µF capacitor and a 30 mH inductor are connected in series with an AC source of voltage 200 V and frequency 50 Hz. Find the impedance and current flow in the circuit.

16. Light radiation of wavelength 6800 A° falls on a photosensitive metal plate of work function 1.8 eV. Find the velocity of ejected photoelectron. (Mass of electron is 1.6×10-31 kg, charge of electron is 1.6×10-19 and speed of light is 3×108 ms¯¹)

17. At what temperature, the velocity of sound in air is increased by 40% to that at 30°C?

18. A capillary tube of 0.3 cm diameter is placed vertically inside a liquid of density 800 kg/m³. Surface tension 5×104 N/m and angle of contact 30°. Calculate the height to which the liquid rises inside the capillary tube.

19. In a Young's double slit experiment, the separation of four bright fringes is 2.5 mm when the wavelength of light used is 6200 Å. The distance of screen from the slits is 0.8 m. Calculate the separation of two slits.

20. An electron is revolving in a uniform magnetic field of strength 1.5x10-2T. The radius of circular path is 1.2×10-2 m. Through what potential difference was the electron initially accelerated from rest? (e/m for electron = 1.77×10¹¹ c/kg)

                                         Good Luck!