Practice Problems -Test 2

1. An isolated positive charge of 12 mC is located at the origin of a coordinate system. The electric potential atinfinity is zero.a. What is the potential energy of 10 mC test charge located at x= 2 cm? ( 0.54 J)b. What is the work required to move the 10 mC test charge from x= 2 cm to x= cm ? (0 J)

2. Four point charges are arranged at the corners of a square as shown in fig.a. What is work done to arrange such a system?Where q1 = -5mC, q2 = +5 m C and L=20 cm.

3.A uniform solid conducting sphere of radiusa = 3 cm carries a charge of 4 mC. The potential due to this chargeis zero at infinity.a. What is the potential at a distance r = 10 cm from the center of the sphere?( 360,000 V)b. What is the potential difference between r = 6 cm and the surface of the sphere ? (600,000 V)

4.In a certain region of space the potential in volts is given by V=50x2 -3000y + 250z2 -100,where the coordinates are in meters.What is x-, y-, and z-component of the electric field?

5. Answer the questions below.a. The rate at which net charge passes through a given cross-sectional area is called-----------b. The average velocity of the carriers in a conductor is called the --------c. The property a conductor to cause it to produce heat when a potential difference is applied across it is its-------d. A device in which non electrical energy is converted into electric energy is called a source of --------e. The ratio of the potential difference across a conductor to the current passing through it is its---f. The unit of resistivity is the -----g. Current density is measured in SI units of -------h. The rate at which heat is dissipated in a resistor is measured in SI unit of -----I. A device that transforms chemical energy into electrical energy is called a -----j. A material in which current can flow without resistance is called a ------

6. Four capacitors are connected as shown in the fig. The two capacitors C1=30 pF each and the two capacitorsC2=60 pF each. A potential difference of 200 V is connected between the outer ends of the combination.a. Find the net capacitance of the combination.b. Find the potential difference across each capacitor.c. Find the charge on each capacitor.d. Find the total energy stored in the combination.e. If all the capacitors are filled with dielectric material whose dielectric constant is K=2, then what would be totalcapacitance of the combination.                              

7.Find the equivalent capacitance of the circuit shown in the diagram. How much charge is separated by thebattery?  where c1 = 3 mF, c2 = 2 mF and V = 10 Volts.

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