KCET · Physics · Waves and Sound
How many times more intense is a \(60 \mathrm{~dB}\) sound than a \(30 \mathrm{~dB}\) sound?
- A 1000
- B 2
- C 100
- D 4
Answer & Solution
Correct Answer
(A) 1000
Step-by-step Solution
Detailed explanation
\(\mathrm{L}=10 \log _{10} \frac{\mathrm{I}}{\mathrm{I}_{0}}\)
\(60=10 \log _{10} \frac{\mathrm{I}_{1}}{\mathrm{I}_{0}}\)
\(\Rightarrow \frac{\mathrm{I}_{1}}{\mathrm{I}_{0}}=10^{6}\)
Similarly,
\(\begin{aligned}&30=10 \log _{10} \frac{\mathrm{I}_{2}}{\mathrm{I}_{0}} \\&\frac{\mathrm{I}_{2}}{\mathrm{I}_{0}}=10^{3}\end{aligned}\)
Dividing Eq. (i) by Eq. (ii), we get
\(\frac{\mathrm{I}_{1}}{\mathrm{I}_{2}}=1000\)
\(60=10 \log _{10} \frac{\mathrm{I}_{1}}{\mathrm{I}_{0}}\)
\(\Rightarrow \frac{\mathrm{I}_{1}}{\mathrm{I}_{0}}=10^{6}\)
Similarly,
\(\begin{aligned}&30=10 \log _{10} \frac{\mathrm{I}_{2}}{\mathrm{I}_{0}} \\&\frac{\mathrm{I}_{2}}{\mathrm{I}_{0}}=10^{3}\end{aligned}\)
Dividing Eq. (i) by Eq. (ii), we get
\(\frac{\mathrm{I}_{1}}{\mathrm{I}_{2}}=1000\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- A metallic sphere of radius R carrying a charge q is kept at certain distance from another metallic sphere of radius \(\mathrm{R} / 4\) carrying a charge Q . What is the electric flux at any point inside the metallic sphere of radius R due to the sphere of radius \(\mathrm{R} / 4\) ?
KCET 2025 Easy - Two solid pieces, one of steel and the other of aluminium when immersed completely in water have equal weights. When the solid pieces are weighed in airKCET 2009 Medium
- Each resistance in the given cubical network has resistance of \(1 \Omega\) and equivalent resistance between \(A\) and \(B\) is
KCET 2020 Medium - Wire bound resistors are made by winding the wires of an alloy ofKCET 2022 Easy
- A car has a fresh storage battery of emf \(12 \mathrm{~V}\) and internal resistance \(2 \times 10^{-2} \Omega\). If the starter motor draws a current of \(80 \mathrm{~A}\). Then, the terminal voltage when the starter is On isKCET 2020 Medium
- Two poles are separated by a distance of \(3.14 \mathrm{~m}\). The resolving power of human eye is \(1 \mathrm{~min}\) of an arc. The maximum distance from which he can identify the two poles distinctly isKCET 2020 Medium
More PYQs from KCET
- General solution of differential equation \( \frac{d y}{d x}+y=1(y \neq 1) \) isKCET 2017 Medium
- The equilibrium constant of the reaction \(\mathrm{A}(\mathrm{s})+2 \mathrm{~B}^{2+}(\mathrm{aq}) \rightleftharpoons \mathrm{A}^{2+}(\mathrm{aq})+2 \mathrm{~B}(\mathrm{~s})\)
\(\mathrm{F}_{\text {cell }}^{\circ}=0.0295 \mathrm{~V}\) is \(\left[\frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.059\right]\)KCET 2012 Medium - If the volume of the parallelopiped formed by three non-coplanar vectors \(\mathbf{a}, \mathbf{b}\) and \(\mathbf{c}\) is 4 cu units, then \([\mathbf{a} \times \mathbf{b} \mathbf{b} \times \mathbf{c} \mathbf{c} \times \mathbf{a}]\) is equal toKCET 2012 Medium
- The length of the chord joining the points \((4 \cos \theta, 4 \sin \theta)\) and \(\left(4 \cos \left(\theta+60^{\circ}\right)\right.\), \(\left.4 \sin \left(\theta+60^{\circ}\right)\right)\) of the circle \(x^{2}+y^{2}=16\) isKCET 2009 Medium
- Damage to thymus in a child may lead toKCET 2009 Medium
- For a cell reaction involving two electron changes, \( E_{\text {cell }}^{\circ}=0.3 \mathrm{~V} \) at \( 25^{\circ} \mathrm{C} \). The cell equilibrium
constant of the reaction isKCET 2018 Medium