Step 1: Identifying the error.
In the sentence, "Saira" is a singular subject, so the correct auxiliary verb should be "does," which agrees with a singular subject.
Step 2: Analyzing the Options.
- (A) How does: This is the correct option. The auxiliary verb "does" is used correctly with the singular subject "Saira."
- (B) How did: This is incorrect because the past tense "did" doesn't match the present context of the sentence.
- (C) How does not: This is grammatically incorrect in this context. "Does not" is used in negative sentences, not questions.
- (D) How has: This is also incorrect because "has" is used for present perfect tense, and the sentence is in simple present tense.
Step 3: Conclusion.
The correct answer is (A) How does, as it correctly matches the subject-verb agreement.
A weight of $500\,$N is held on a smooth plane inclined at $30^\circ$ to the horizontal by a force $P$ acting at $30^\circ$ to the inclined plane as shown. Then the value of force $P$ is:
A steel wire of $20$ mm diameter is bent into a circular shape of $10$ m radius. If modulus of elasticity of wire is $2\times10^{5}\ \text{N/mm}^2$, then the maximum bending stress induced in wire is: