PHY102

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

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

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

4.  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?

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

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

7. Electric field is measured in Newton per ---------------------------.

8. An alpha particle is a --------------------------- nucleus consisting of 2 protons and 2 neutrons.

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

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

11. Neutral objects constitute of equal ---------------------------

12.  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.

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

14.  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

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

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

17. The study of static charges is called ---------------------------

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

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

20.  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?

21. 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.

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

23. 1eV is the energy acquired by an electron in falling freely through --------------------------- 1volt.

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

25.  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}

26. 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.

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

28.  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 $Q_{2}$

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

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

31. 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.

32.  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.

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

34.  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

35.  Which of the following is a conductor

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

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

38.  An ac circuit consists of a voltage source $v = 200sin120pi{t}$ and a $6mu$F capacitor in series. Calculate the current established in the circuit

39. The force between electric charges is known as ---------------------------

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

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

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

43. 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?

44.  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 $0.5Omega$

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

46. A uniform electric field of 200 N/C is in the x-direction. A point charge of 3mu{C} is released from rest at the origin. What is the kinetic energy of the charge when it is at x = 4 m?

47. 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?

48. 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}

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

50. The following are true about electric field lines except that they ______