An electric dipole is placed at an angle of \(30^o \) with an electric field intensity \(2 \times \,\,10^5 \,\,NC^{-1}\) It experiences a torque equal to \(4\,\, N m.\) The charge on the dipole, if the dipole length is \(2\,\, cm,\) is

A \(5 \,\,mC\)
B \(7\) \(\mu \;C\)
C \(8\,\, mC\)
D \(2\,\, mC\)

Verified Solution

Answer & Solution

Correct Answer

(D) \(2\,\, mC\)

Step-by-step Solution

Detailed explanation

Here, \(\theta = {30^\circ },E = 2 \times {10^5}\,{\text{N}}{{\text{C}}^{ - 1}}\) \(\tau = 4\,{\text{Nm}},l = 2\,{\text{cm}} = 0.02\,{\text{m}},q = ?\)

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

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Match the following enzymes with their functions

\((a)\) Restriction endonuclease	\((i)\) Joins the \(DNA\) fragements
\((b)\) Restriction exonuclease	\((ii)\) Extends primers on genomic \(DNA\) template
\((c)\) \(DNA\) ligase	\((iii)\) Cuts \(DNA\) at specific position
\((d)\) Taq polymerase	\((iv)\) Removes nucleotides from the ends of \(DNA\)

Select the correct option from the following

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