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QJEEM23Ph8fe5: JEE Main 2023 Physics - Class 11 JEEM23Ph8fe5 Solution: When vector is subtracted from vector , it gives a vector equal …

When vector A⃗=2i^+3j^+2k^\vec{A}=2 \hat{i}+3 \hat{j}+2 \hat{k} is subtracted from vector B→\overrightarrow{\mathrm{B}} , it gives a vector equal to 2j^2 \hat{j} . Then the magnitude of vector B→\overrightarrow{\mathrm{B}} will be :

Multiple Choice Options

  • A 3
  • B 33\sqrt{33}
  • C 6\sqrt6
  • D 5\sqrt5

Step-by-Step Verified Solution

Given that when vector A⃗=2i^+3j^+2k^\vec{A}=2 \hat{i}+3 \hat{j}+2 \hat{k} is subtracted from vector B→\overrightarrow{\mathrm{B}} , it gives a vector equal to 2j^2 \hat{j} .

We can write this as:

B⃗−A⃗=2j^\vec{B} - \vec{A} = 2 \hat{j}

Now, let's express the vector B→\overrightarrow{\mathrm{B}} in terms of its components:

B⃗=Bxi^+Byj^+Bzk^\vec{B} = B_x \hat{i} + B_y \hat{j} + B_z \hat{k}

Subtract vector A⃗\vec{A} from vector B⃗\vec{B} :

(Bxi^+Byj^+Bzk^)−(2i^+3j^+2k^)=2j^(B_x \hat{i} + B_y \hat{j} + B_z \hat{k}) - (2 \hat{i}+3 \hat{j}+2 \hat{k}) = 2 \hat{j}

Comparing the components, we get:

Bx−2=0By−3=2Bz−2=0B_x - 2 = 0 \\B_y - 3 = 2 \\B_z - 2 = 0

Solving these equations, we find the components of vector B⃗\vec{B} :

Bx=2By=5Bz=2B_x = 2 \\B_y = 5 \\B_z = 2

Now, we can find the magnitude of vector B⃗\vec{B} :

∣B⃗∣=Bx2+By2+Bz2=22+52+22=4+25+4=33|\vec{B}| = \sqrt{B_x^2 + B_y^2 + B_z^2} = \sqrt{2^2 + 5^2 + 2^2} = \sqrt{4 + 25 + 4} = \sqrt{33}

Therefore, the magnitude of vector B→\overrightarrow{\mathrm{B}} is 33\sqrt{33}

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