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Physics · Electrostatics

NEET (UG) 2023 — Question 29

An electric dipole is placed at an angle of 30∘30^{\circ} with an electric field of intensity 2×105 NC−12 \times 10^{5} \mathrm{~N} \mathrm{C}^{-1}. It experiences a torque equal to 4 N m . Calculate the magnitude of charge on the dipole, if the dipole length is 2 cm .

  1. Option A:

    6 mC

  2. Option B:

    4 mC

  3. Option C:

    2 m C

    Correct
  4. Option D:

    8 mC

Answer: C

Step-by-step solution

E=2×105 N/CI=2 cmτ=4Nmτ⃗=p⃗×E⃗4=pEsin⁡θ4=p×2×105×sin⁡30∘p=4×10−5 cmq=pl=4×10−50.02=2mC\begin{aligned} & E=2 \times 10^5 \mathrm{~N} / \mathrm{C} \\ & I=2 \mathrm{~cm} \\ & \tau=4 \mathrm{Nm} \\ & \vec{\tau}=\vec{p} \times \vec{E} \\ & 4=p E \sin \theta \\ & 4=p \times 2 \times 10^5 \times \sin 30^{\circ} \\ & p=4 \times 10^{-5} \mathrm{~cm} \\ & q=\frac{p}{l}=\frac{4 \times 10^{-5}}{0.02}=2 \mathrm{mC}\end{aligned}

Answer key and solution verified before publishing.

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Exam
NEET (UG) 2023
Paper
2023 paper
Subject
Physics
Chapter
Electrostatics
Topic
Electric Dipole

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