Electric Circuits Answers

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?

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.

The diameter of 0---guage copper wire is 8.252 mm. Find the resistance of a 1.00-km length of such wire used for power transmission.

A 330-ohm resistor is connected to a 5-volt battery. The current through the resistor is?

Two circuits present the same resistance to the current. In one circuit the battery causing the flow of current has a voltage of 9.0 V, and the current is 3.0 A. In the other circuit the battery has a voltage of 1.5 V. What is the current in this other circuit?

A lightning bolt delivers a charge of 35 C to the ground in a time of 1.0*10^-3 s. What is the current?

In 2.0 s, 1.9*10¹⁹ electrons pass a certain point in a wire. what it the current / in the wire?

In series circuit, the voltmeter reads 120V. Find what is (a.) the combined resistance (b) the potential differences across the combination (c) the voltage across the 30ꭥ resistor and (d) the current flows through the 10ꭥ resistor?

Three identical capacitors are connected with a resistor in two different circuits. When they are connected in series, the time constant to charge up this circuit is 0.02s. What is the time constant when they are connected as in parallel?

A 150-V battery is connected across two parallel metal plates of area 28.5 cm² and separation 8.20 mmm. A beam of alpha particles (charge +2ê , mass 6.64 x 10-²⁷ kg) is accelerated from rest through a potential difference of 1.75 kV and enters the region between the plates perpendicular to the electric field. What magnitude and direction of magnetic field are needed so that the alpha particles emerge undeflected from between the plates?

Two charges Q1=+3.5 nC and Q2=-5.3 nC are separated by 10 cm. Calculate the electric potential at point B