Two lamps of 16 and 36 candela respectively are 1.0 m apart. Where should a screen be placed between them so that it is equally illuminated on both sides?

Two free point charges each of +4q and +q are placed at a distance a apart. Where should a third point charge Q be placed between them so that the entire system is in equilibrium?

Two polaroids A and B are kept in crossed poisiton.How should a third polariod C be placed between them so that the intensity of polarised ligth transmitted by polaroid B reduces to 1//8th of the intensity of unpolarised light incident on A?

A convex and concave lens having focal lengths of 30 cm and j10 cm respectively are placed at a distance 20 cm from each other.Whre should a source of light be placed so that the system of the two lenses will produce a beam of parallel rays?

Two equal magnetic poles placed 25 cm apart in air exert a fore o 4xx10^-3N on each other. What should be the distance between them, so that force exerted by them on each other becomes 0.1 N?

In a Young's double slit experiment,two slits are 1.5 mm apart and a screen in placed at a distance 1.2 m from the plane of the slits .The slits are illuminated with light of wavelength 6,000 overset @A .Find the inimum distance from the central maximum for which the intensity is half of the maximum intensity.

Two lenses of power +10 D and -5 D are placed in contact. Where should an object be held from the lens,so as to obtain a virtual image of magnification 2?

A rod of length 1.05 m having negligible mass is supported at its ends by two wires of steel (wire A) and aluminium (wire B) of equal lengths as shown in Fig. 9.15. The cross-sectional areas of wires A and B are 1.0 mm^2 and 2.0 mm^2 , respectively. At what point along the rod should a mass m be suspended in order to produce equal strains in both steel and aluminium wires.:

In a Young's double slit experiment,interfernce fringes were produced on a screen placed at 1.5 m from the two slits 0.3 mm apar and illuminated by ligth of 6,400 overset@A .Find the fringe width.

Two charges +-10muC are placed 5.0 mm apart. Determine the electric field at a point on the axis of the dipole 15 cm away from its centre 0 on the side of the positive charge

In the equilibrium 2SO_(2)(g)+O_(2)(g)hArr2SO_(3)(g) , the partial pressure of SO_(2),O_(2) and SO_(3) are 0.662,0.10 and 0.331 atm respectively . What should be the partial pressure of Oxygen so that the equilibrium concentrations of SO_(3) are equal ?