1
WB JEE 2021
+2
-0.5
For a plane electromagnetic wave, the electric field is given by

$$\overrightarrow{E} = 90\sin (0.5 \times {10^3}x + 1.5 \times {10^{11}}t)\widehat k$$ V/m. The corresponding magnetic field B will be
A
$$\overrightarrow{B} = 3 \times {10^{ - 7}}\sin (0.5 \times {10^3}x + 1.5 \times {10^{11}}t)\widehat i$$ T
B
$$\overrightarrow{B} = 3 \times {10^{ - 7}}\sin (0.5 \times {10^3}x + 1.5 \times {10^{11}}t)\widehat j$$ T
C
$$\overrightarrow{B} = 27 \times {10^9}\sin (0.5 \times {10^3}x + 1.5 \times {10^{11}}t)\widehat j$$ T
D
$$\overrightarrow{B} = 3 \times {10^{ - 7}}\sin (0.5 \times {10^3}x + 1.5 \times {10^{11}}t)\widehat k$$ T
2
WB JEE 2020
+1
-0.25
Consider a conducting wire of length L bent in the form of a circle of radius R and another conductor of length a (a < < R) is bent in the form of a square. The two loops are then placed in same plane such that the square loop is exactly at the centre of the circular loop. What will be the mutual inductance between the two loops?
A
$${\mu _0}{{\pi {a^2}} \over L}$$
B
$${\mu _0}{{\pi {a^2}} \over 16L}$$
C
$${\mu _0}{{\pi {a^2}} \over 4L}$$
D
$${\mu _0}{{{a^2}} \over {4\pi L}}$$
3
WB JEE 2020
+2
-0.5
A conducting circular loop of resistance 20$$\Omega$$ and cross-sectional area 20 $$\times$$ 10-2 m2 is placed perpendicular to a spatially uniform magnetic field B, which varies with time t as B = 2sin(50$$\pi$$t) T. Find the net charge flowing through the loop in 20 ms starting from t = 0.
A
0.5 C
B
0.2 C
C
0 C
D
0.14 C
4
WB JEE 2018
+2
-0.5
As shown in the figure, a rectangular loop of conducting wire is moving away with a constant velocity v in a perpendicular direction from a very long straight conductor carrying a steady current I. When the breadth of the rectangular loop is very small compared to its distance from the straight conductor, how does the emf. E induced in the loop vary with time t?

A
$$E \propto {1 \over {{t^2}}}$$
B
$$E \propto {1 \over t}$$
C
$$E \propto \ln (t)$$
D
$$E \propto {1 \over {{t^3}}}$$
WB JEE Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
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