MHT CET · Physics · Ray Optics
A concave mirror of focal length ' \(f\) ' produces an image ' \(n\) ' time the size of the object. If the image is real, then the distance of the object from the mirror is
- A \((\mathrm{n}-1) \mathrm{f}\)
- B \(\left(\frac{n-1}{n}\right) \mathrm{f}\)
- C \(\left(\frac{\mathrm{n}+1}{\mathrm{n}}\right) \mathrm{f}\)
- D \((\mathrm{n}+1) \mathrm{f}\)
Answer & Solution
Correct Answer
(C) \(\left(\frac{\mathrm{n}+1}{\mathrm{n}}\right) \mathrm{f}\)
Step-by-step Solution
Detailed explanation
As the image is real and inverted Magnification,
\(-\mathrm{n}=\frac{-\mathrm{v}}{\mathrm{u}}\) where \(\mathrm{u}=\) distance of the object
\(\therefore \quad v=n u\)
By mirror formula,
\(\begin{array}{ll}
& \frac{1}{\mathrm{f}}=\frac{1}{\mathrm{v}}+\frac{1}{\mathrm{u}} \\
\therefore & \frac{1}{\mathrm{f}}=\frac{1}{\mathrm{nu}}+\frac{1}{\mathrm{u}} \\
\therefore \quad & \mathrm{u}=\left(\frac{\mathrm{n}+1}{\mathrm{n}}\right) \mathrm{f}
\end{array}\)
\(-\mathrm{n}=\frac{-\mathrm{v}}{\mathrm{u}}\) where \(\mathrm{u}=\) distance of the object
\(\therefore \quad v=n u\)
By mirror formula,
\(\begin{array}{ll}
& \frac{1}{\mathrm{f}}=\frac{1}{\mathrm{v}}+\frac{1}{\mathrm{u}} \\
\therefore & \frac{1}{\mathrm{f}}=\frac{1}{\mathrm{nu}}+\frac{1}{\mathrm{u}} \\
\therefore \quad & \mathrm{u}=\left(\frac{\mathrm{n}+1}{\mathrm{n}}\right) \mathrm{f}
\end{array}\)
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
- Which one of the following person is in an inertial frame of reference?MHT CET 2025 Easy
- Water is flowing through a horizontal pipe in stream line flow. At the narrowest part of the pipeMHT CET 2023 Easy
- In hydrogen atom spectrum, when an electron jumps from second excited state to the first excited state, the wavelength of radiation emitted is ' \(\lambda\) '. If the electron jumps from the third excited state to the second orbit, the wavelength of radiation emitted will be \(20 \lambda / x\). The value of \(x\) isMHT CET 2025 Medium
- A stretched string fixed at both ends has ‘m’ nodes, then the length of the string will beMHT CET 2019 Easy
- Two parallel wires of equal lengths are separated by a distance of \(3 \mathrm{~m}\) from each other. The currents flowing through \(1^{\text {st }}\) and \(2^{\text {nd }}\) wire is \(3 \mathrm{~A}\) and \(4.5 \mathrm{~A}\) respectively in opposite directions. The resultant magnetic field at mid point between the wires \(\left(\mu_0=\right.\) permeability of free space)MHT CET 2023 Hard
- The magnetic field at the centre of a circular coil of radius ' \(R\) ', carrying current \(2 \mathrm{~A}\) is ' \(\mathrm{B}_1\) '. The magnetic field at the centre of another coil of radius ' \(3 R\) ' carrying current \(4 A\) is ' \(B_2\) '. The ratio \(B_1: B_2\) isMHT CET 2023 Medium
More PYQs from MHT CET
- Which one of the following represents correctly the variation of volume (V) of an ideal gas with temperature \((\mathrm{T})\) under constant pressure conditions?
MHT CET 2023 Easy - According to Raoult's law mole fraction of solute in solution is given by formulaMHT CET 2021 Easy
- If \(y=\tan ^{-1}\left[\sqrt{\frac{1+\cos \frac{x}{2}}{1-\cos \frac{x}{2}}}\right]\), then \(\frac{d y}{d x}=\)MHT CET 2020 Easy
- If \(\mathrm{f}(x)=x^3-10 x^2+200 x-10\), thenMHT CET 2024 Easy
- The angle subtended by the vector \(\vec{A}=4 \hat{\imath}+3 \hat{\jmath}+12 \hat{k}\) with the \(\mathrm{x}\) -axis isMHT CET 2020 Easy
- Which of the following metals is refined by vapour phase refining in Mond process?MHT CET 2020 Easy