Current and resistance introduction problem The following table gives the length

Question

Current and resistance introduction problem The following table gives the lengths of three copper rods, their diameters, and the potential differences between their ends. Rod Length Diameter Potential Difference 1 L 3d V 2 2L d 2V 3 3L 2d 2V (a) Rank the rods according to the magnitude of the electric field within them, greatest first (use only the symbols > or =, for example 1>2=3). (b) Rank the rods according to the current density within them, greatest first (use only the symbols > or =, for example 1>2=3). (c) Rank the rods according to the drift speed of electrons through them, greatest first (use only the symbols > or =, for example 1>2=3).

Explanation / Answer

a)

electric field is given E=Voltage/length

so E1=V/L ,E2=2V/2L =(V/L) ,E3=(2V/3L)=(2/3)(V/L)

SO

1=2>3

B)

Current density J=I/A =V/R/A =V/(pL/A)*A =V/pL

J1 =(V/pL) ,J2=(2V/p2L)=(V/pL)

J3=(2/3)(V/pL)

1=2>3

c)

v=uE

1=2>3

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.