Correct Answer: A. sodium oxochlorate (I)

Correct Answer: B. Said that the Vineyard was near his House

Correct Answer: D. simile

Explanation

(a) Resonance occurs whenever a particular body or system is set in oscillation at its own natural frequency as a result of impulses received from some other body or system which is vibrating with the same frequency. At resonance, the amplitude is maximum. Two examples of resonance are tuning a radio and divers board.

Procedure: In the diagram above the string is kept taut by using a constant weight

(w) between the two bridges A and B. The length, L between the bridges is adjusted until the wire resonates with the vibrating tuning fork. This happens when a paper rider flies off or when a loud sound is heard. Then, measure length, L of the resonating wire and frequency f. The experiment is repeated for at least four other tuning forks of known frequencies. In each case the values of the frequency, f and the corresponding length, L are recorded. A graph of f is plotted against 1/L or L against 1/f. A straight-line graph passing through origin is obtained showing that frequency is proportional to the reciprocal of the length.

(iii) Precautions:

(1) A smooth pulley should be used

(2) the tuning fork should be struck on a rubber bung

(c) For a fundamental note

f\(_o\) = \(\frac{1}{20}\) = \(\sqrt{\frac{T}{m}}\)

where f\(_o\) = fundamental frequency

L = Length of string

T = Tension m = linear density or mass per unit length of the string

(i) \(f_1 = \frac{1}{20} \sqrt{\frac{f}{m}}\) = 3(\(\frac{1}{20} \sqrt{\frac{1}{20}} \sqrt{\frac{1}{m}})\)

f\(_1 = 3f_o\)

i.e = the fundamental frequency, \(f_o\) is tripled

(ii) \(f_2 = \frac{1}{20} (\frac{1}{20} \sqrt{\frac{T}{m}}) = \frac{1}{2} \times \frac{1}{20} \sqrt{\frac{1}{m}} = f_2 = \frac{1}{2} f_o\)

i.e the fundamental frequency, \(f_o\) is halved

Correct Answer: C. Samaria

Explanation

\(y = \frac{x - 1}{2x + 1}, x \neq -\frac{1}{2}\)

Using the quotient rule, we have

\(\frac{\mathrm d y}{\mathrm d x} = \frac{(2x + 1). 1 - (x - 1). 2}{(2x - 1)^{2}}\)

= \(\frac{2x + 1 - 2x + 2}{(2x + 1)^{2}}\)

\(\frac{\mathrm d y}{\mathrm d x} = \frac{3}{(2x + 1)^{2}}\)

At (1, 0), \(\frac{\mathrm d y}{\mathrm d x} = \frac{3}{(2(1) + 1)^{2}} = \frac{3}{9} = \frac{1}{3}\)

Equation : \(\frac{y - 0}{x - 1} = \frac{1}{3}\)

\(y = \frac{1}{3}(x - 1)\)

Correct Answer: D. -1< x ≤ 2

Correct Answer: C. it is used for the purification of copper

Correct Answer: B. subscript

Correct Answer: A. is fabicated and untrue