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Consider the two-dimensional vector field F(x,y)=x î+y ĵ, where î and ĵ denote the unit vectors along the x-axis and the y-axis, respectively. A contour C in the x-y plane, as shown in the figure, is composed of two horizontal lines connected at the ends by two semicircular arcs of unit radius. The contour is traversed in the counter-clockwise sense. The value of the closed path integral ∮_C F(x,y)· (dx î+dy ĵ) is _________.
- 0
- 1
- 8 + 2π
- −1
Correct answer: 0
Solution
The vector field ( ext{F}(x,y) = x ext{hat{i}} + y ext{hat{j}}) is conservative, meaning that the line integral over any closed path is zero. This is because the field can be expressed as the gradient of a scalar potential function, which implies that the integral around a closed contour yields no net work done.
Related GATE Engineering Mathematics questions
- A vector field p and a scalar field r are given by
p = (2x² - 3xy + z²) î + (2y² - 3yz + x²) ĵ + (2z² - 3xz + x²) k̂
r = 6x² + 4y² - z² - 9xyz - 2xy + 3xz - yz
Consider the statements P and Q.
P: Curl of the gradient of the scalar field r is a null vector.
Q: Divergence of curl of the vector field p is zero.
Which one of the following options is CORRECT?
- What is curl of the vector field 2x²y i + 5z² j − 4yzk ?
- Let φ be a scalar field, and u be a vector field. Which of the following identities is true for div(φu)?
- A delivery agent is at a location R. To deliver the order, she is instructed to travel to location P along straight-line paths of RC, CA, AB and BP of 5 km each. The direction of each path is given in the table below as whole circle bearings. Assume that the latitude (L) and departure (D) of R is (0, 0) km. What is the latitude and departure of P (in km, rounded off to one decimal place)? Paths: RC, CA, AB, BP. Directions (in degrees): 120, 0, 90, 240.
- Three vectors p, q and r are given as p = î + ĵ + k̂, q = î + 2ĵ + 3k̂, r = 2î + 3ĵ + 4k̂. Which of the following is/are CORRECT?
- If a vector field V is related to another vector field A through V = ∇ × A, which of the following is true? Note: C and S_c refer to any closed contour and any surface whose boundary is C.
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