Question

A block in the shape of a rectangular solid has a crosssectional area of 3.50 cm2 across its width, a front-to-rear length of 15.8 cm, and a resistance of 935 0. The block’s material contains 5.33 $ 1022 conduction electrons/m3. A potential difference of 35.8 V is maintained between its front and rear faces. (a) What is the current in the block? (b) If the current density is uniform, what is its magnitude? What are (c) the drift velocity of the conduction electrons and (d) the magnitude of the electric field in the block?

Answer 1

a) 38.3mA

b) 109.396A/m^2

c) 1.283cm/s

d) 226.582V/m

Step-by-step explanation:

The equation for current is given by:

I = V/R = 35.6/ 935 = 0.03829 A Approximately 38.3mA

b) The equation to find the magnitude is given by:

J = I/A = 0.03829/ 0.000350m^2

J = 109.396A/m^2

c) The equation to calculate drift velocity of the electron is given by: Vd = J/ ne = 109.396/( 5.33×10^23 )(1.60×10^-19)

Vd = 0.01283 approximately 1.283cm/s

d) The magnitude of electric field in the block, E = V/L = 35.8/ 0.158m = 226.582V/m