Question
A point source S is placed midway between two converging mirrors having equal focal length f. Find the values of d for which only one image is formed.
✓
Answer
Both the mirrors have equal focal length f.They will produce one image under two conditions.
Case I: When the source is at distance ‘2f’ from each mirror i.e. the source is at centre of curvature of the mirrors, the image will be produced at the same point S. So, d = 2f + 2f = 4f.
Case II: When the source S is at distance ‘f’ from each mirror, the rays from the source after reflecting from one mirror will become parallel and so these parallel rays after the reflection from the other mirror the object itself. So, only sine image is formed.
Here, d = f + f = 2f
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
A boy riding on his bike is going towards east at a speed. of $4\sqrt{2}\text{m/s}$ At a certain point he produces a sound pulse of frequency $1650Hz$ that travels in air at a speed of $334m/s$. A second boy stands on the ground $45°$ south of east from him. Find the frequency of the pulse as received by the second boy.
→$4.0g$ of helium occupies $22400cm^3$ at STP. The specific heat capacity of helium at constant pressure is $5.0cal-K^{-1}mol^{-1}$. Calculate the speed of sound in helium at STP.
→Write Kelvin-Planck and Clausius statements for second law of thermodynamics. Define coefficient of efficiency and coefficient of performance. Show the heat flow in case of an engine and refrigerator using schematic diagrams.
A ball is dropped from a building of height 45m. Simultaneously another ball is thrown up with a speed 40m/s. Calculate the relative speed of the balls as a function of time.
Each of the resistors shown in figure. has a resistance of $10\Omega$ and each of the batteries has an emf of 10V. Find the currents through the resistors a and b in the two circuits.
→Find the magnetic field B at the centre of a rectangular loop of length l and width b, carrying a current i.
The friction coefficient between the horizontal surface and each of the blocks shown in figure is 0.20. The collision between the blocks is perfectly elastic. Find the separation between the two blocks when they come o rest. Take $g = 10 m/s^2.$
→In the arrangement shown in figure $y = 1.0mm. d = 0.24mm$ end $D = 1.2m$. The work function of the materiel of the emitter is $2.2eV$. Find the stopping potential V needed to stop the photocurrent.
→A hundred metre sprinter increases his speed from rest uniformly at the rate of $1m/s^2$ for three quarters of the length and covers the last quarter with a uniform speed. How long does he take to cover the first half and second half of the run?
→A conducting square loop having edges of length 2.0cm is rotated through 180° about a diagonal in 0.20s. A magnetic field B exists in the region which is perpendicular to the loop in its initial position. If the average induced emf during the rotation is 20mV, find the magnitude of the magnetic field.