Two similar thin equi-convex lenses, of focal length f each, are kept coaxially in contact with each other such that the focal length of the combination is F1. When the space between the two lenses is filled with glycerin (which has the same refractive index (μ = 1.5) as that of glass) then the equivalent focal length is F2.TheratioF1 :F2 willbe:

Anonymous User Physics Ray Optics 20 Apr, 2020 2 Answer 111 views

















One conducting U tube can slide inside another as shown in figure, maintaining electrical contacts between the tubes. The magnetic field B is perpendicular to the plane of the figure. If each tube moves towards the other at a constant speed v, then the emf induced in the circuit in terms of B, l and v where l is the width of each tube, will be

Anonymous User Physics Magnetostatics 19 Apr, 2020 1 Answer 65 views

A metal conductor of length 1 m rotates vertically about one of its ends at angular velocity 5 radian per second. If the horizontal component of earth’s magnetic field is 0.2 × 10-4 T, then the e.m.f. developed between the two ends of the conductor

Anonymous User Physics Magnetostatics 19 Apr, 2020 1 Answer 60 views


In a uniform magnetic field of induction B a wire in the form of a semicircle of radius r rotates about the diameter of the circle with angular frequency . The axis of rotation is perpendicular to the field. If the total resistance of the circuit is R the mean power generated per period of rotation is

Anonymous User Physics Magnetostatics 19 Apr, 2020 1 Answer 63 views

A coil having n turns and resistance R  is connected with a galvanometer of resistance 4R . This combination is moved in time t seconds from a magnetic field W1 weber to W2 weber. The induced current in the circuit is

Anonymous User Physics Magnetostatics 19 Apr, 2020 1 Answer 59 views











The length of a magnet is large compared to its width and breadth. The time period of its oscillation in a vibration magnetometer is 2 s. The magnet is cut along its length into three equal parts and three parts are then placed on each other with their like poles together. What will be the time period of this combination? 

Anonymous User Physics Magnetostatics 18 Apr, 2020 1 Answer 57 views

There are several types of enzyme catalysed reactions. In
one type of enzyme catalysed reaction, in addition to the
catalytic site to which the substrate (X) binds, the enzyme
also has a site to which some other substance (Y) can bind.
When Y binds to such an enzyme, the enzyme can still bind
to the substrate but cannot convert it to the product. Which
of the following will occur in such a case?

Anonymous User Biology 18 Apr, 2020 1 Answer 67 views



During the growth of marine fish, initially, yolk sac and skin are the principal sites where transport protein ‘x’ is located. Later, skin and gills become principal sites and finally ‘x’ becomes localised to gills. The protein ‘x’ is

Anonymous User Biology 18 Apr, 2020 1 Answer 67 views


Two identical conducting wires AOB and COD are placed at right angles to each other. The wire AOB carries an electric current I1 and COD carries a current I2. The magnetic field on a point lying at a distance d from O, in a direction perpendicular to the plane of the wires AOB and COD, will be given by

Anonymous User Physics Magnetic Effect of Current 17 Apr, 2020 1 Answer 66 views


A charged particle with charge q enters a region of constant, uniform and mutually orthogonal fields and  with a velocity  perpendicular to both and , and comes out without any change in magnitude or direction of . Then

Anonymous User Physics Magnetic Effect of Current 17 Apr, 2020 1 Answer 59 views