PHY102

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

2.  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?

3. The potential difference between two points B and A is equal to the --------------------------- in taking a unit positive charge from A to B.

4. 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.

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

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

7.  Which of the following is a conductor

8.  If the steady current in a wire is coming directly toward you, the magnetic field lines

9.  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?

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

11. 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

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

13. When beta decay occurs --------------------------- changes into a proton and electron.

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

15. The energy stored in a system of charges is known as electrostatic potential ---------------------------

16. Electric flux density is a function of ---------------------------

17.  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?

18. 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}

19. An RLC circiut contains an ac voltage source with rms value of 50V and has a frequency of 600Hz. Suppose that a resistance R = 20 $Omega$, capacitance C = 10.0 $mu$F and an inductance L = 4.0mH are connected in series to the source. Find the current in the circuit and the voltmeter reading across the inductor.

20. Property of magnetic material in which --------------------------- attracts or repels.

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

22.  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?

23. A positively charged object repels

24.  1 volt is equal to ________

25.  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

26. 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?

27. 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.

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

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

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

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

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

33. 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?

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

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

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

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

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

39. When a copper surface is illuminated by radiation of wavelength 2537 angstrome units the value of the stopping potential is found to be 0.24volts. Calculate the work function of copper.

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

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

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

43.  Two identical balls balls P and Q, each of mass 0.20 g, carry identical charges and are suspended by two threads of equal length. The balls position themselves at equilibrium such that the angle between the threads is 60_{o}.If the distance between the the balls is 0.5m, find the charge on each of them. Take g = 9.8 m/s^{2}

44.  Two charges $Q_{1} = 500mu{C}$ and $Q_{2} = 100mu{C}$ are located on the XY plane at the positions $r_{1} = 3vec{j} m and r_{2} = 4vec{i}$ m. Find the force exerted on the $Q_{2}$

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

46. 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 ---------------------------

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

48. Potential difference is the work done in moving a unit charge ____ from one point to another in an electric field.

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

50.  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?