PHY102

1. A body that absorbs all radiations falling on it is known as ---------------------------.

2. When an atom is in the ground state it is said to be ---------------------------

3.  A magnetic field does not exert a force on a _________

4. When amber is rubbed with fur

5. The force that is responsible for holding electrons to nuclei to form atoms is called the --------------------------- force

6. Which of the following is not true of an electrostatic force?

7. Calculate the electric field at distance of 320 cm from an infinitely long wire carrying a charge per unit length 8.3 C/m.

8. Kirchhof's junction rule is statement of conservation of -----------

9. The electric flux is a --------------------------- quantity.

10. A tiny ball of mass 0.60 g is suspended from a rigid support with a piece of thread in a horizontal electric field of intensity 700 N/C. The ball is in equilibrium when the thread is inclined at an angle of 20_{o} to the vertical. What are the magnitude and sign of the charge on the ball? Take g = 9.8m/s^{2}

11. An RLC circuit is used to tune a radio set to receive NOUN RADIO broadcasting at 105.9MHz in the FM band. The resistance and the inductance of the circuit of the radio set are $12Omega$ and 1.4$mu$H respectively. What capacitance should the circuit have?

12.  The work function of a metal is 3.45eV. Calculate th maximum wavelength of a photon that can eject photo-electrons from the metal

13. The half-life of a certain radioactive isotope is 32 hours. What fraction of the sample would remain after 16 hours?

14. The --------------------------- is the SI Unit of electric charge

15. 1eV is the energy acquired by an electron in falling freely through --------------------------- 1volt.

16. For capacitors in parallel, the potential difference across each capacitor is ---------------------------

17. A negative charge ---------------------------negative charge

18. In the cathode ray oscilloscope, when fast moving electrons strike the glass screen coated with zinc and sulphide they cause ---------------------------.

19. The resistivity of a semiconductor decreases rapidly with increasing ---------------------------.

20.  1 volt is equal to ________

21. As charge increases, electric flux density ­---------------------------

22. A positive ion passes through an electric and magnetic fields which are mutually perpendicular. The electric field strength is 20.0kV/m while the magnetic flux density is 0.40T. At what speed will the ion pass through undeflected?

23. What is the self - inductance of an air-core solenoid, 1m long and 0.05m in diameter, if it has 1400 turns?

24. The magnitude and direction of the earth's field varies with position over the --------------------------- surface.

25. The variation of the compass from the north-south direction is called the ---------------------------

26.  A rectangular coil of dimensions 20 cm by 15 cm lies with its plane parallel to a magnetic field of $ 0.5 W/$m^{2}$. The coil, carrying a current of 10 A experiences a torque of 4.5 Nm in the field. How many loops has the coil?

27. Field lines are drawn such that the lines per unit cross-section area is proportional to ---------------------------field.

28.  The term 'lost volts' refers to -----------

29.  A huge spark due to electric discharge in the atmosphere produces all of the following except ______

30. The work done in taking a unit positive charge from one point to another in electric field is --------------------------- of the path chosen between the two points.

31. A region where an electric charge experiences a force is ---------------------------field

32.  In the space surrounding a wire carrying a steady current, there exists ________

33.  An air-cored transformer is assumed to be 100% efficient. The ratio of the secondary turns to the primary turns is 1:20. A 240V ac supply is connected to the primary coil and a $6Omega$ load is connected to the secondary coil. what is the current in the primary coil?

34.  A series circuit consisting of an uncharged $42mu$F capacitor and $10 MOmegaega$ resistor is connected to 100V power source. What are the current in the circuit and the charge on the capacitor after one time constant?

35.  Which of the following is a conductor

36.  An ammeter is suspected of giving inaccurate readings. In order to confirm the readings, the ammeter is connected to a silver votltameter in series and a steady current is passed for one hour. The ammeter reads 0.56A and 2.0124g of silver is deposited. What is the error is the ammeter reading?

37. For how long must a steady current of 2A flow through a copper voltameter to deposit $10^{-3}$kg of copper? Z for coper is 0.000329g/C

38. Gauss's law applies to any hypothetical closed surface called --------------------------- surface.

39. When a charge density depends only on the perpendicular distance from a plane, the charge distribution is said to have--------------------------- symmetry.

40. The magnetic North is found by suspending a bar magnet freely on the --------------------------- axis.

41.  A conductor 2cm long carrying a current of 8A lies at right angles to a magnetic field of which the flux density is 1.0T. Calculate the force exerted on the conductor

42.  A single turn coil of cross-sectional area $7.2cm^2$ is in the a magnetic field of flux desity 0.45T. The field which is perpendicular to the coil, is steadily reduced to 0.0T in 5s. Calculate the induced emf.

43. The --------------------------- number is the total number of neutrons and protons.

44. The direction of the electric field is opposite to that of the force if the charge is ---------------------------

45. For capacitors connected in series each has the same ____________.

46. At the _______ a dipping compass needle is horizontal and at the magnetic poles it is vertical.

47. According to Faraday's law, the magnitude of the induced e.m.f is proportional to the rate of change of --------------------------- linking the circuit.

48. A voltmeter connected across a 60Hz ac source reads 240V. Write down the expression of the instanteneous voltage as a function of time.

49. The surface integral of the electric field E over a surface is defined to be electric ---------------------------

50.  From Gauss’ law which of the following is NOT correct?