What is the focal length of a convex lens, Physics

Assignment Help:

Q. What is the focal length of a convex lens of focal length 30 cm in contact with a Concave lens of focal length 20 cm ? Is the system a converging or a diverging lens?

Ignore thickness of the lenses.

Answer

A Focal length of the convex lens f1 = 30cm

A Focal length of the concave lens f2 = - 20cm

A  Focal length of the system of lenses = f

The equal focal length of a system of two lenses in contact is given as

656_What is the focal length of a convex lens.png

Hence the focal length of the combination of lenses is 60 cm. The negative sign specifies that the system of lenses acts a diverging lens.


Related Discussions:- What is the focal length of a convex lens

Wave motion-lenses, You are given 3 lenses l1,l2,l3 each of focal length 20...

You are given 3 lenses l1,l2,l3 each of focal length 20 an object at 40cm in front of l1.the final real image is formed at focus i ofl3,find separation between l1,l2,l3 ? Ans) bet

The magnetic circuit, THE MAGNETIC CIRCUIT In an electric circuit, a cu...

THE MAGNETIC CIRCUIT In an electric circuit, a current is established due to the existence of an electromotive force. In the same way, in a magnetic circuit, a flux is establis

At what time do the cars meet, Two cars head out in the similar direction. ...

Two cars head out in the similar direction. Car A starts 1.0 min before car B. The position-time graphs for both cars are shown in the accompanying figure. a. How far apa

#biot''s polariscope., Ask question #whether s component or p component pre...

Ask question #whether s component or p component present in the reflected light of Biot''s polariscope# Minimum 100 words accepted#

Determine the component of the force, Water flows through a right angle val...

Water flows through a right angle valve at the rate of 1000 lbm/s as shown in the figure. The pressure just upstream of the valve is 90 psi and the pressure drop across the valve i

How atom was postulated when electrons revolved in orbits, The idea that el...

The idea that electrons revolved in orbits around the nucleus of an atom without radiating energy away from the atom was postulated by: a) Thompson b) Bohr c) Ruther

Find the coefficient of self induction, Q. An emf of 5 V is persuading when...

Q. An emf of 5 V is persuading when the current in the coil changes at the rate of 100 As-1. Find the coefficient of self induction. Solution: Induced emf   e = - L dI/dt

Rectilinear motion, An elevator is stopped at the ground floor. It starts m...

An elevator is stopped at the ground floor. It starts moving upwards at constant acceleration a>0 for 5 seconds. It then keeps a constant speed for 35 seconds. Finally, it slows do

Variation of temperature according to newton''s law, Variation of temperatu...

Variation of temperature of a body according to Newton's law: Let Consider a system has a temperature Φi at time t = 0. It is placed in an environment whose temperature is Φ0. We a

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd