Electric Circuits Answers

Find the value of the electric field at a distance r=10 cm from the center of a non-conducting sphere of radius R=1 cm which has an extra positive charge equal to 7 C uniformly distributed within the volume of the sphere.

the bridge rectifier is preferred to an ordinary two diode full wave rectifier becuase

A battery consisting of three identical cells, each with internal resistance of 1.0 Ω is connected in a series with

5.0 Ω and 3.0 Ω resistors. The voltage across the 5 Ω resistor is 5V. Determine the (a) current flowing through the circuit, (b) voltage across the 3 Ω resistor, (C) terminal voltage of the cell, and (d) electromotive force of the cell.

Suppose the resistance is 1.47 Ω at a temperature of 20°C. Find the resistance at 0 degree Celsius.

Describe in a creative way the effect of temperature increases on the resistance of a metallic conductor. Also, describe the ability of the material to conduct current in terms of its resistivity and conductivity.

Note: You may express your answer through a drawing, just by making a slogan or a poster. It is all up to you as long as you can describe

1. A resistor with resistance R = 30 MΩ is connected in series with a capacitor with capacitance 3 μF. What is the

time constant?

2. Determine the equivalent (total) resistance for each of the following circuits below.

1. Why do lights on a car become dimmer when you start a car?

2. Some Christmas tree lights have a characteristic that when one light (filament) burns out, the lights throughout go

out too. However, burned-out lights go out in other series lights. Discuss the difference between these two sets of

lights.

1. Find the current density and drift velocity of free electrons when the particles travel on a copper conductor with a square cross-section of 1.0 mm on the side and carries a current of 40 A to a 5 hp electric meter and its density of 6.0 x 1028 electrons/m3

2. Suppose the resistance is 1.47 Ω at a temperature of 20°C. Find the resistance at 0 degree Celsius.

1. How would you expect the resistivity of a good insulator such as glass or polystyrene to vary with temperature?

2. A fuse is a device that is designed to break the circuit. It melts when the current exceeds its value. What

characteristics should the material have?

Two point charges are placed as follows: charge q_{1} = - 1.50nC is at y = 6.00 m and charge q_{2} = 3.20nC is at the origin. What is the total force (magnitude and direction) exerted by these two charges on a negative point charge q_{3} = - 5.00nC located at (2.00 m, -4.00 m)?