A parallel plate capacitor with circular plates of radius 1 m has a capacitance of 1 nF. At t = 0, it is connected for charging in series with a resistor R = 1 MΩ across a 2V battery (as shown in the figure). Find the magnetic field at a point P, halfway between the centre and the periphery of the plates, after t = 10–3 s. (The charge on the capacitor at time t is (t) = CV[1 – exp (–t/τ)], where the time constant τ is equal to CR.) 

1. 0.74×10-13 T
2.  0.67×10-13 T
3.  0.74×10-12 T
4. 0.67×10-12 T

Subtopic:  Maxwell's Equations |
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NEET 2023 - Target Batch - Aryan Raj Singh
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A plane electromagnetic wave of frequency 25 MHz travels in free space along the x-direction. At a particular point in space and time, \(\vec{E_{0}}=6.3~ \hat{j}~V/m\)What is \(\vec{B_{0}}\) at this point?
1. \(2.1\times 10^{-8} \hat{k}~\text{T}\)
2. \(1.2\times10^{-8} \hat{k}~\text{T}\)
3. \(2.1\times10^{-8} \hat{j}~\text{T}\)
4. \(1.2\times10^{-8} \hat{j}~\text{T}\)

Subtopic:  Properties of EM Waves |
 77%
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NEET 2023 - Target Batch - Aryan Raj Singh
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The magnetic field in a plane electromagnetic wave is given by \(\mathrm{B}=\left(2 \times 10^{-7}\right) \mathrm{T} \sin \left(0.5 \times 10^3 \mathrm{x}+1.5 \times 10^{11} \mathrm{t}\right )\). The wavelength and frequency of the wave are respectively:

1. \( 2.16 \mathrm{~cm}, 24.1 \mathrm{~GHz} \)
2. \( 0.29 \mathrm{~cm}, 13.7 \mathrm{~GHz} \)
3. \( 3.23 \mathrm{~cm}, 20.0 \mathrm{~GHz} \)
4. \( 1.26 \mathrm{~cm}, 23.9 \mathrm{~GHz}\)

Subtopic:  Properties of EM Waves |
 70%
From NCERT
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To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

The magnetic field in a plane electromagnetic wave is given by \(\mathrm{B}=\left(2 \times 10^{-7}\right) \mathrm{T} \sin \left(0.5 \times 10^3 \mathrm{x}+1.5 \times 10^{11} \mathrm{t}\right)\). The expression for the electric field is:
1. \( \mathrm{E}_{\mathrm{z}}=60 \sin \left(0.5 \times 10^3 \mathrm{x}+1.5 \times 10^{11} \mathrm{t}\right) \mathrm{V} / \mathrm{m} \)
2. \( \mathrm{E}_{\mathrm{z}}=60 \sin \left(1.5 \times 10^3 \mathrm{x}+0.5 \times 10^{11} \mathrm{t}\right) \mathrm{V} / \mathrm{m} \)
3. \( \mathrm{E}_{\mathrm{z}}=55 \sin \left(0.5 \times 10^3 \mathrm{x}+1.5 \times 10^{11} \mathrm{t}\right) \mathrm{V} / \mathrm{m} \)
4. \( \mathrm{E}_{\mathrm{z}}=55 \sin \left(1.5 \times 10^3 \mathrm{x}+0.5 \times 10^{11} \mathrm{t}\right) \mathrm{V} / \mathrm{m}\)

Subtopic:  Properties of EM Waves |
 81%
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NEET 2023 - Target Batch - Aryan Raj Singh
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Light with an energy flux of 18 W/cm2 falls on a non-reflecting surface at normal incidence. If the surface has an area of 20 cm2, what is the average force exerted on the surface during a 30 minute time span?

1. 2.1×10-6 N
2. 1.8×10-6 N
3. 1.2×10-6 N
4. 2.1×10-5 N

Subtopic:  Properties of EM Waves |
 55%
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NEET 2023 - Target Batch - Aryan Raj Singh
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Assume a bulb of efficiency \(2.5\%\) as a point source. The peak values of the electric field and magnetic field produced by the radiation coming from a \(100~\mathrm{W}\) bulb at a distance of \(3~\mathrm{m}\) are respectively:

1. \( 2.5 \mathrm{~V} / \mathrm{m}, ~2.2 \times 10^{-8} \mathrm{~T} \)
2. \( 3.6 \mathrm{~V} / \mathrm{m},~ 3.6 \mathrm{~T} \)
3. \( 4.07 \mathrm{~V} / \mathrm{m},~ 1.4 \times 10^{-8} \mathrm{~T} \)
4. \( 4.2 \mathrm{~V} / \mathrm{m}, ~3.4 \times 10^{-6} \mathrm{~T}\)

Subtopic:  Properties of EM Waves |
 53%
From NCERT
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NEET 2023 - Target Batch - Aryan Raj Singh
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