Question

What is the resistance of the coil A at 600 kelvin if its resistance at 300 kelvin is 50 ohms? (Assume the temperature coefficient of resistance of the coil is .007/ degrees C)

Answer 1

155Ω

Explanation:

R = R ref ( 1 + ∝ ( T - Tref)  

where R = conduction resistance at temperature T

R ref = conductor resistance at reference temperature

∝ = temperature coefficient of resistance for conductor

T = conduction temperature in degrees Celsius

T ref = reference temperature that ∝ is specified at for the conductor material

T = 600 k - 273 k = 327 °C

Tref = 300 - 273 K = 27 °C

R = 50 Ω ( 1 + 0.007 ( 327 - 27) )

R = 155Ω

Answer 2

Answer:

155 ohms

Explanation:

Resistance is the opposition to the flow of electric current via a conductor. The expression bellow is used in calculating the resistance of a coil given the temperature coefficient of resistance of the coil;

R = Rn [1 + α (T - Tn)]

where

R is the conductor's resistance at T temperature

Rn is the conductor's resistance at Tn temperature

α is the temperature coefficient of resistance of conducting material

T is the conductor's temperature

Tn is the conductor's reference temperature.

The conduct in question is a coil,

given  

R = ?

Rn = 50 ohms

α = 0.007/°C

T = 600 Kelvin

Tn = 300 Kelvin

Using the equation R = Rn [1 + α (T - Tn)] we substitute to find R

R = 50 [1 + 0.007 (600-300)]

using BODMAS The inner bracket comes first followed by multiplication, addition and then the outer bracket.

R = 155 ohms