PHY102

1.  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?

2.  A spectral line is emitted when an atom undergoes transition between two levels with a difference in energy of 2.4eV. What is the wavelength of the line?

3. The force applied to a conductor is 10N if the charge in the conductor is 5C, what is the electric field intensity?

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

5. A charge distribution in which the charge density at any point depends only on the distance of the point from a central point and not on the direction is said to be spherically ---------------------------

6. According to ohm's law the potential difference is proportional to the ---------------------------

7. In the method of charging by friction, The algebraic sum of the individual charges that is the net charge is ---------------------------.

8.  Which of the following is a conductor

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

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

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

12.  What are the dimensions of the constant k in Coulomb’s law of electrostatics?

13. Electric charge between two bodies can be produced by ---------------------------

14. Gaussian surface is an imaginary closed ---------------------------

15. A negative charge ---------------------------negative charge

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

17. Three point charges $$2mu{C$}, ${-}4mu{C}$$, and $$6mu{C}$$ are held at the corners of an equilateral triangle with sides equal to 3 cm.What is the resultant force in newtons on the $$2mu{C}$$ charge?

18. The magnitude of the forces between charged spheres was first investigated by Charles ---------------------------

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

20. <p style="text-align:left">Six equal point charges Q = 10nC are located at 2,3, 4,5,6,7m. Find the potential at origin.

21.  Which of the following can be used to charge a metal rod that si held in your hand? Rub it with ______

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

23. Whose law is employed in electrostatics ­­?

24.  The magnetic flux through each loop of a 35-loop coil is given by $(3.6t-0.71t^{3})times10^{-2}Tm^{2}$, where the time is in seconds. Determine the induced emf at t=5.0s.

25.  Kirchhof's loop rule is statement of conservation of __________

26.  An electron enters a uniform magnetic field 0.20 T at an angle of $30^{o}$ the field. Determine the pitch of the helical path assuming its speed is $3times10^{7}$ m/s

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

28.  Find the current in through the $0.3Omega$ in the circuit shown

29. 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?

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

31. 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}

32.  1 volt is equal to ________

33.  In the circuit shown, each of the cells has an emf of 2V and internal resistance of $0.1Omega$. Find the current in through the $0.5Omega$

34. A galvanometer of resistance $120Omega$ a full scale deflection with a current of 0.0005A. How would you convert it to an ammeter that reads a maximum current of 5A?

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

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

37. Charges of ${+}2$ C and ${-2}$ C are situated at points P and Q respectively which are at a distance apart. A point X is mid-way between P and Q. Which of the following correctly describes the electric field and the electric potential at point X?

38. The principle that electric forces add vectorially is known as the principle of ---------------------------

39. 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.

40. A proton is accelerated through a potential difference of 100V and the enters a region in which it is moving perpendicular to a magnetic field of flux density 0.20 T. Find the radius of the circular path in which it will travel.

41.  A potentiometer wire of length 100cm has a resistance of 10$Omega$. It is connected in series to to a resistance R and a cell of emf 2V and negligible internal resistance. A source of emf of 10mV is balanced by a length of 40cm of the potentiometer wire. What is the value of the resistance R?

42.  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?

43.  An electric field of 50 kV/m is perpendicular to a magnetic field 0.25 T. What is the velocity of a charge whose initial of motion is perpendicular to both fields and which passes through the fields undeflected?

44.  Which of the following is not true about the electric field intensity $vec{E}$ of a uniformly charged solid sphere?

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

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

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

48.  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.

49. Find the force on a charge 2C in a field 1Vm^-1---------------------------

50. The minimum energy required to liberate an electron from a metal surface is called ---------------------------.