Calculate the diameter of a 0.04-cm length of tungsten filament in a small lightbulb if its resistance is 22 2. If 70mA current flows through the filament, find the potential difference across the source. (a) the diameter of the wire (in m) = (b) Potential difference across the source in V =

A 50.0 m long Aluminum wire has a diameter of 0.50 mm and is at 20.0°C. If it carries a current of 0.50 mA, (a) calculate the power delivered to it? (b) If the temperature is increased to 340°C and the potential difference across the wire remains constant, what is the power delivered?

The current in a 3.0 V battery of a pocket calculator is 0.17 mA. In one hour of operation, (a) how much charge flows in the circuit and (b) how much energy does the battery deliver to the calculator circuit?

What is the current travelling through a cellphone charger when 0.20 mC of electronspass a point in 0.75 min? Answer in amperes and microamperes (μA).

The cord from an appliance is too short to reach the wall outlet in your room. You have two extension cords to choose from. (a) Find the voltage drop in the first extension cord having a 0.0360 resistance and through which 6.20 A is flowing. v (b) The second extension cord is cheaper and utilizes thinner wire. It has a resistance of 0.072 N and the current flowing through it is 6.20 A. By what amount does the voltage supplied to the appliance change when the first extension cord is replaced by the second?

An electric utility company supplies a customer's house from the main power lines (120 V) with two copper wires, each of which is 46.0 m long and has a resistance of 0.109 2 per 300 m. (a) Find the potential difference at the customer's house for a load current of 102 A. V (b) For this load current, find the power delivered to the customer. kW

In a certain article, laser therapy was discussed as a useful alternative to drugs in pain management of chronically ill patients. To measure pain threshold, a machine was used that delivered low-voltage direct current to different parts of the body (wrist, neck, and back). The machine measured current in milliamperes (mA). The pretreatment experimental group in the study had an average threshold of pain (pain was first detectable) at ? = 3.19 mA with standard deviation ? = 1.03 mA. Assume that the distribution of threshold pain, measured in milliamperes, is symmetric and more or less mound-shaped. (Round your answers to two decimal places.) (a) Use the empirical rule to estimate a range of milliamperes centered about the mean in which about 68% of the experimental group will have a threshold of painfrom  mA to  mA(b) Use the empirical rule to estimate a range of milliamperes centered about the mean in which about 95% of the experimental group will have a threshold of painfrom  mA to…

A 215-KV power transmission line carrying 500 A is hung from grounded metal towers by ceramic insulators, each having a 1.10 x 10 resistance. (a) What is the resistance to ground of 50 of these insulators? (Assume the insulators are connected in parallel.) 2.267 Q (b) Calculate the power dissipated by 50 of them. X What is the voltage across the effective resistance? How can you find the power from the voltage and the resistance? W (c) What fraction of the power carried by the line is this? P x Protal What is the total power carried by the line?

Current and Resistance Problem 17:   An unknown wire in a circuit has a circular cross-section with diameter 2.5 mm. It carries a current of 8.8 mA. Part (a)  What is the current density, in milliamperes per square centimeter, in this wire?   Part (b)  If you assume the drift velocity in this wire is 1 × 10-2 cm/s, what is the density of charge carriers per cubic centimeter? Part (c)  If the conductivity in this wire is 1.5 × 106 Ω-1 m-1, what is the average time between collisions, in nanoseconds?

Problem 1. A 50.0 m long Aluminum wire has a diameter of 0.50 mm and is at 20.0°C. If it carries a current of 0.50 mA, (a) calculate the power delivered to it? (b) If the temperature is increased to 340°C and the potential difference across the wire remains constant, what is the power delivered?