JEE Main 2021 (Online) 26th August Morning Shift | Magnetics Question 90 | Physics

JEE Main 2021 (Online) 26th August Morning Shift

MCQ (Single Correct Answer)

-1

The fractional change in the magnetic field intensity at a distance 'r' from centre on the axis of current carrying coil of radius 'a' to the magnetic field intensity at the centre of the same coil is : (Take r < a)

$${3 \over 2}{{{a^2}} \over {{r^2}}}$$

$${2 \over 3}{{{a^2}} \over {{r^2}}}$$

$${2 \over 3}{{{r^2}} \over {{a^2}}}$$

$${3 \over 2}{{{r^2}} \over {{a^2}}}$$

JEE Main 2021 (Online) 27th July Evening Shift

MCQ (Single Correct Answer)

-1

Figure A and B shown to long straight wires of circular cross-section (a and b with a < b), carrying current I which is uniformly distributed across the cross-section. The magnitude of magnetic field B varies with radius r and can be represented as :

JEE Main 2021 (Online) 27th July Evening Shift Physics - Magnetics Question 93 English

JEE Main 2021 (Online) 27th July Evening Shift Physics - Magnetics Question 93 English

JEE Main 2021 (Online) 27th July Evening Shift Physics - Magnetics Question 93 English Option 1

JEE Main 2021 (Online) 27th July Evening Shift Physics - Magnetics Question 93 English Option 2

JEE Main 2021 (Online) 27th July Evening Shift Physics - Magnetics Question 93 English Option 3

JEE Main 2021 (Online) 27th July Evening Shift Physics - Magnetics Question 93 English Option 4

JEE Main 2021 (Online) 25th July Evening Shift

MCQ (Single Correct Answer)

-1

Two ions having same mass have charges in the ratio 1 : 2. They are projected normally in a uniform magnetic field with their speeds in the ratio 2 : 3. The ratio of the radii of their circular trajectories is :

1 : 4

4 : 3

3 : 1

2 : 3

JEE Main 2021 (Online) 25th July Morning Shift

MCQ (Single Correct Answer)

-1

A linearly polarized electromagnetic wave in vacuum is

$$E = 3.1\cos \left[ {(1.8)z - (5.4 \times {{10}^6})t} \right]\widehat iN/C$$

is incident normally on a perfectly reflecting wall at z = a. Choose the correct option

The wavelength is 5.4 m

The frequency of electromagnetic wave is 54 $$\times$$ 10⁴ Hz.

The transmitted wave will be $$3.1\cos \left[ {(1.8)z - (5.4 \times {{10}^6})t} \right]\widehat iN/C$$

The reflected wave will be $$3.1\cos \left[ {(1.8)z + (5.4 \times {{10}^6})t} \right]\widehat iN/C$$

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