AP EAMCET · PHYSICS · Ray Optics
An optician prescribes a corrective lens of power \(+2 \mathrm{D}\), then the focal length of the required convex lens is
- A \(10 \mathrm{~cm}\)
- B \(50 \mathrm{~cm}\)
- C \(10 \mathrm{~m}\)
- D \(50 \mathrm{~m}\)
Answer & Solution
Correct Answer
(B) \(50 \mathrm{~cm}\)
Step-by-step Solution
Detailed explanation
Power of a lens in diopters, \(P=\frac{100}{f}\) \(f=\) Focal length of lens in \(\mathrm{cm}\). here, \[ P=+20 \mathrm{D} \] so, \[ 2=\frac{100}{f(\mathrm{~cm})} \Rightarrow f(\mathrm{~cm})=\frac{100}{2}=50 \] \(\therefore\) Focal length of lens \(=50 \mathrm{~cm}\).
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
- Two capillary tubes of same length each of but of different radii and are connected in series. When water flows, the pressure difference between the ends of the arrangement is . Then the pressure difference between the ends of the first tube isAP EAMCET 2019 Easy
- Two light waves of intensities I and 21 superimpose on each other, If the path difference between the light waves reaching a point is \(12.5 \%\) of the wavelength of the light, then the resultant intensify at the point is (Both the light waves have same wavelength)AP EAMCET 2024 Medium
- Two charged particles each of mass \(9.8 \mathrm{~g}\) and charges \(+20 \mu \mathrm{C}\) and \(-20 \mu \mathrm{C}\) are attached to the two ends of a massless and rigid uniform non-conducting rod of length \(50 \mathrm{~cm}\). This arrangement is held in a uniform electric field of \(12.1 \mathrm{NC}^{-1}\), such that the rod makes a very small angle with the field direction. If the rod is set free, the minimum time needed for the rod to become parallel to the direction of the electric field is ................ seconds.AP EAMCET 2018 Hard
- A wire loop of irregular shape carrying current is placed in an external magnetic field. If the wire is flexible, the shape of the loop changes toAP EAMCET 2023 Easy
- A \(50 \mathrm{~g}\) ice cube at \(-10^{\circ} \mathrm{C}\) is added to \(200 \mathrm{~g}\) of water at \(30^{\circ} \mathrm{C}\). The final temperature of the mixture is (specific heat of water \(=1 \mathrm{cal} \mathrm{g}^{-1}{ }^{\circ} \mathrm{C}^{-1}\), latent heat of fusion of ice \(=80 \mathrm{cal} \mathrm{g}^{-1}\) specific heat of ice \(=0.5 \mathrm{cal} \mathrm{g}^{-1}\) \({ }^{\circ} \mathrm{C}^{-1}\) )AP EAMCET 2023 Easy
- A body is projected horizontally from the top of a tower of height with a velocity of . If acceleration due to gravity is then match the following.
The correct answer isList-I List-II Velocity of the body after second in ) (I) Horizontal displacement of the body after second (in meters) (ii) Vertical displacement of the body after second (in meters) (iii) Vertical velocity of the body after second in ) (iv) AP EAMCET 2018 Medium
More PYQs from AP EAMCET
- The refracting angle of a prism is \(A\) and the refractive index of the material of the prism is \(\cot (A / 2)\). The angle of minimum deviation of the prism isAP EAMCET 2004 Easy
- A Circle S passes through the points of intersection of the circles \(x^2+y^2-2 x+2 y-2=0\) and \(x^2+y^2+2 x-2 y+1=0\). If the centre of this circle S lies on the line \(x-y+6=0\), then the radius of the circle \(S\) isAP EAMCET 2024 Easy
- The standard Gibbs' energy change for Daniel cell reaction is
\[
\begin{aligned}
& \mathrm{Zn}(s)+\mathrm{Cu}^{2+}(a q) \longrightarrow \mathrm{Zn}^{2+}(a q)+\mathrm{Cu}(s) \\
& E_{\text {cell }}^{\circ}=1.1 \mathrm{~V} \text {. }
\end{aligned}
\]AP EAMCET 2022 Easy - The roots \(\alpha, \beta\) of the equation \(x^2-6(k-1) x+4(k-2)=0\) are equal in magnitude but opposite in sign. if \(\alpha>\beta\), then the product of the roots of the equation \(2 \mathrm{x}^2-\alpha \mathrm{x}+6 \beta(\alpha+1)=0\) isAP EAMCET 2025 Medium
- A ball falls freely from rest on to a hard horizontal floor and repeatedly bounces. If the velocity of the ball just before the first bounce is \(7 \mathrm{~ms}^{-1}\) and the coefficient of restitution is 0.75 . The total distance travelled by the ball before it comes to rest is (acceleration due to gravity \(=10 \mathrm{~ms}^{-2}\) )AP EAMCET 2024 Hard
- \(\int_0^1 \sqrt{\frac{2+x}{2-x}} d x=\)AP EAMCET 2024 Hard