Q5. Figure shows drift speed Va of conduction electrons in a copper wire versus position (X) for the

Q: What is the correct answer for CUET UG Physics Q5?

The correct answer is c. The drift speed (Vd) of conduction electrons is related to the current (I) and the cross-sectional area (A) by Vd = I / (neA), where n is the number density of electrons and e is the electron charge. Since the current (I), n, and e are constant, Vd is inversely proportional to the cross-sectional area (A), and thus inversely proportional to the square of the radius (r). From the graph, Vd_I > Vd_I

Q: Q5. Figure shows drift speed Va of conduction electrons in a copper wire versus position (X) for the three sections. Then, Vd ΙⅡⅢ X (A) Radius of III > Radius of II > Radius of I (B) Electric Field…

The correct answer is c. The drift speed (Vd) of conduction electrons is related to the current (I) and the cross-sectional area (A) by Vd = I / (neA), where n is the number density of electrons and e is the electron charge. Since the current (I), n, and e are constant, Vd is inversely proportional to the cross-sectional area (A), and thus inversely proportional to the square of the radius (r). From the graph, Vd_I > Vd_I

Q: What are the options for this CUET UG Physics question?

A. (D) only · B. (B) and (D) only · C. (A) and (D) only · D. (B) and (C) only

Question

Q5. Figure shows drift speed Va of conduction electrons in a copper wire versus position (X) for the three sections. Then,
Vd
ΙⅡⅢ
X
(A) Radius of III > Radius of II > Radius of I
(B) Electric Field in III > Electric Field in II > Electric Field in I
(C) Radius of wire is same in all sections
(D) Conductivity is same in all sections
Choose the correct answer from the options given below:
(a) (D) only
(b) (B) and (D) only
(c) (A) and (D) only
(d) (B) and (C) only

FirstInTest · Accepted Answer

The drift speed (Vd) of conduction electrons is related to the current (I) and the cross-sectional area (A) by Vd = I / (neA), where n is the number density of electrons and e is the electron charge. Since the current (I), n, and e are constant, Vd is inversely proportional to the cross-sectional area (A), and thus inversely proportional to the square of the radius (r). From the graph, Vd_I > Vd_II > Vd_III. This implies A_I < A_II < A_III, and consequently, r_I < r_II < r_III. So, statement (A) 'Radius of III > Radius of II > Radius of I' is correct. For a uniform copper wire, the material properties like conductivity (σ) remain constant throughout its length, regardless of its radius. Thus, statement (D) 'Conductivity is same in all sections' is correct. The electric field E = Vd / μ (where μ is mobility), so E is proportional to Vd. Thus, E_I > E_II > E_III, making statement (B) incorrect (it states E_III > E_II > E_I). Statement (C) is incorrect as drift speeds differ, implying different radii. Therefore, the correct combination of statements is (A) and (D).

Answer

(D) only

Answer

(B) and (D) only

Answer

(A) and (D) only

Answer

(B) and (C) only

Related Questionsin Physics

More from CUET UG

Browse CUET Questions by Subject

Practice More CUET UG Questions