Question 1
If a vector field [Tex]\vec{V}[/Tex] is related to another vector field [Tex]\vec{A}[/Tex] through [Tex]\vec{V} = \nabla \times \vec{A}[/Tex]. Which of the following is true?
Note: C and S refer to any closed contour and any surface whose boundary is C.
(GATE 2009 || EC || MCQ ||2 MARK)
[Tex]\oint_{c} \vec{V} \cdot d\vec{l} = \iint_{s_e} \vec{A} \cdot d\vec{S}[/Tex]
[Tex]\oint_{c} \vec{A} \cdot d\vec{l} = \iint_{s_e} \vec{V} \cdot d\vec{S}[/Tex]
[Tex]\oint_{c} (\nabla \times \vec{V}) \cdot d\vec{l} = \iint_{s_e} (\nabla \times \vec{A}) \cdot d\vec{S}[/Tex]
[Tex]\oint_{c} (\nabla \times \vec{A}) \cdot d\vec{l} = \iint_{s_e} \vec{V} \cdot d\vec{S}[/Tex]
Question 2
Consider a closed surface S surrounding a volume V. If [Tex]\overrightarrow{\rm r}[/Tex] is the position vector of a point inside S, with [Tex]\hat{n}[/Tex] the unit normal on S, the value of the integral [Tex]\iint_{S} 5\overrightarrow{\rm \vec{r}} \cdot \hat{n} \, dS[/Tex] is
(GATE 2011 || EC || MCQ ||2 MARK)
3 V
5 V
10 V
15 V
Question 3
The direction of vector [Tex]\vec{A}[/Tex] is radially outward from the origin, with [Tex]|\vec{A}| = kr^n[/Tex] where [Tex]r^2 = x^2 + y^2 + z^2[/Tex] and k is a constant. The value of $n$ for which [Tex]\nabla \cdot \vec{A} = 0[/Tex] is
(GATE 2012|| EC || MCQ ||1 MARK)
-2
2
1
0
Question 4
A vector [Tex]\overrightarrow{\rm P}[/Tex] is given by
[Tex]\overrightarrow{\rm P} = x^3 y\overrightarrow{\rm a}_x - x^2 y^2 \overrightarrow{\rm a}_y - x^2 y z \overrightarrow{\rm a}_z[/Tex]
Which of the following statements is TRUE?
(GATE 2015|| EC || MCQ ||2 MARK)
P is solenoidal but not irrotational
[Tex]\overrightarrow{\rm P}[/Tex] is irrotational but not solenoidal
[Tex]\overrightarrow{\rm P}[/Tex] is neither solenoidal nor irrotational
[Tex]\overrightarrow{\rm P}[/Tex] is both solenoidal and irrotational
Question 5

(GATE 2015|| EC || NAT ||2 MARK)
78.53
Question 6
If the vector function [Tex]\vec{F} = (3y - k_1 z)\vec{a}_x + (k_2 x - 2z)\vec{a}_y - (k_3 y + z)\vec{a}_z[/Tex] is irrotational, then the values of the constants [Tex]k_1, k_2[/Tex] and [Tex]k_3[/Tex] respectively, are
(GATE 2017|| EC || MCQ ||2 MARK)
0.3, –2.5, 0.5
0.0, 3.0, 2.0
0.3, 0.33, 0.5
4.0, 3.0, 2.0
Question 7
For a vector field [Tex]\vec{A}[/Tex] , which one of the following is FALSE?
(GATE 2020|| EC || MCQ ||1 MARK)
[Tex]\vec{A} \text{ is solenoidal if } \nabla \cdot \vec{A} = 0[/Tex]
[Tex]\nabla \times \vec{A} \text{ is also another vector field}[/Tex]
[Tex]\vec{A} \text{ is irrotational if } \nabla^2 \vec{A} = 0[/Tex]
[Tex]\nabla \times (\nabla \times \vec{A}) = \nabla (\nabla \cdot \vec{A}) - \nabla^2 \vec{A}[/Tex]
Question 8

(GATE 2021|| EC || NAT ||1 MARK)
56.55
There are 8 questions to complete.