« previous next »

Author Question: The temperature coefficient of resistivity of iron is 5.0 10-3 / C; that of carbon is -0.50 10-3 / ... (Read 52 times)

Destiiny22

  • Hero Member
  • *****
  • Posts: 557
on: Jul 28, 2018
The temperature coefficient of resistivity of iron is 5.0  10-3 / C; that of carbon is -0.50  10-3 / C. When an iron wire and a carbon rod, each having the same 10 W resistance at 20C, are cooled from that temperature to -80C, the new ratio of the resistance of the carbon rod to the resistance of the iron wire at the lower temperature is
 a. -0.10.
  b. +1.9.
  c. +2.1.
  d. -10.
  e. +10.

Question 2

If a mile of 24-gauge copper wire has a resistance of 0.14 kW and the resistivity of copper is 1.7  10-8 W  m, what is the diameter of the wire? (1 mile = 1.6 km)
 a. 0.40 mm
  b. 0.50 mm
  c. 0.63 mm
  d. 0.80 mm
  e. 0.25 mm


juicepod

  • Sr. Member
  • ****
  • Posts: 310
Reply #1 on: Jul 28, 2018
Answer to Question 1

C

Answer to Question 2

B


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.

Did you know?

Patients who have been on total parenteral nutrition for more than a few days may need to have foods gradually reintroduced to give the digestive tract time to start working again.

Did you know?

The Food and Drug Administration has approved Risperdal, an adult antipsychotic drug, for the symptomatic treatment of irritability in children and adolescents with autism. The approval is the first for the use of a drug to treat behaviors associated with autism in children. These behaviors are included under the general heading of irritability and include aggression, deliberate self-injury, and temper tantrums.

Did you know?

Throughout history, plants containing cardiac steroids have been used as heart drugs and as poisons (e.g., in arrows used in combat), emetics, and diuretics.

Did you know?

The heart is located in the center of the chest, with part of it tipped slightly so that it taps against the left side of the chest.

Banded iron formations Banded iron formations
Metabolic reactions involving synthesis, interconversion, and utilization of one-carbon adducts of t Metabolic reactions involving synthesis, interconversion, and utilization of one-carbon adducts of t
Carbon Isotope ratio Carbon Isotope ratio
Stomatal density and carbon dioxide Stomatal density and carbon dioxide
Leaf margins and air temperature Leaf margins and air temperature
Kidney beans, steak, and iron-fortified bread and cereal are good sources of iron Kidney beans, steak, and iron-fortified bread and cereal are good sources of iron
Video: Photosynthesis overview Animation

For a complete list of videos, visit our video library