A wire of length l and resistance R is bent in the form of a ring. The resistance between two points which are separated by angle is?

Volume of a gas at a particular temperature and on atmospheric pressure is 200 ml. Keeping the temperature constant if pressure is increased to 5 atmosphere, then volume of the gas will be(if P1V1 = P2V2 )

a stationary obj at 4 deg cal and weighing 3.5kg falls from height of 2000 m on snow mountain at 0 degc if temp of obj just hitting snow is 0 deg and obj comes to rest immediately obj melt at (latent heat of ice=3.5*10^5 j/s)

how many g of a liquid of speific heat 0.2 at a temp 40 deg cal must be mixed with 100 gm of liquid of speciic heat 0.5 at temp 20 deg cal so that final temp of mix becomes 32 dg cal

A block of mass m is placed on an another rough block of mass M and both are moving horizontally with same acceleration a due to a force which is applied on the lower block, then work done by lower block on the upper block in moving a distance s will be?

A particle moves on a rough horizontal ground with some initial velocity say v0. If (3/4)th of its kinetic energy is lost due to friction in time t0 then coefficient of friction between the particle and the ground is?

Two balls are dropped from the same point after an interval of 1 second. Their separation 3 second after the release of the second ball. (g = 10 m/s2)

A string of linear mass density 0.8 kg/m is stretched to a tension 500 N. The mean power required to maintain a travelling wave of amplitude of 10 mm and wavelength 0.5 m is?

A particle is projected with a speed u in air at angle θ with the horizontal. The particle explodes at the highest point of its path into two equal fragments, one of the fragments moving up straight with a speed u. The difference in time in which the two particle fall on the ground is (Assume it is at a height H at the time of explosion)

If inside a big circle exactly 24 small circles, each of radius 2, can be drawn in such a way that each small circle touches the big circle and also touches both its adjacent small circles, then radius of the big circle is?

The differential equation of the system of circles touching the x-axis at origin is?

Two particles of mass M = 3 kg each are kept on a horizontal circular platform on two mutually perpendicular radii at equal distance R = 1 m from the centre of the table. The particles are connected with a string, which is just taught when the platform is not rotating. Coefficient of friction between the platform and block is = 0.1. Then the maximum angular speed ( in rad/sec) of platform about its centre so that the blocks remain stationary relative to platform. (take g = 10 m/s2)

A spring is compressed between two blocks of masses m1 and m2 placed on a horizontal frictionless surface. When the blocks are released. The blocks travel distance x1 and x2 respectively before coming to rest. The ratio x1/x2 is?

A cylinder has a radius r. To what height h should it be filled with water so that the thrust on its walls is equal to that on its bottom

A swimmer can swim in still water with a speed of speed is 3 m/s. If he cross the river in the shortest possible time, what is the speed of flow of water?

Two balls are dropped from the same point after an interval of 1 second. Their separation 3 second after the release of the second ball? (g = 10 m/s2)

Clianostat is associated with :-

The number of permutations of the letters of the word HINDUSTAN such that neither the pattern ‘HIN’ nor ‘DUS’ nor ‘TAN’ appears, are

Number of ways in which 7 girls & 7 boys can be arranged such that no two boys and no two girls are together is?

Number of ways in which 5 identical objects can be distributed in 8 persons such that no person gets more than one object is?

The number of flags with three strips in order that can be formed using 2 identical red, 2 identical blue and 2 identical white strips is

The number of ways of selecting two numbers from the set {1, 2, ...,12} whose sum is divisible by 3 is?

The C = C bond dissociation energy is 146 kcal/mole whereas C – C bond dissociation energy is 83 kcal/mole then whey paraffins are less reactive than olefins.

Why Al(OH)3 is amphoteric in nature?

A diatomic molecule has dipole moment of 1.2 D. If the bond distance is 1.0 A. What fraction of an electronic charge ‘e’ exists on each atom?

Two positive point charge of 12 uc and 8 uc are 10 cm apart the. Work done in bringing them 4 cm close is

Compare the bond energies of

O-nitrophenol is more volatile than p-nitrophenol. Explain?

p-isomer will be having highest dipole moment since dipole moment of – CF3 group is reinforced to maximum extent in this case by – CH3 group. (One is electron withdrawing and other is electron releasing.

Calculate the percentage of ionic character of HI having bond length = 1.62Å and observed dipole moment = 0.39 D.

Na2CO3 does not decompose on heating whereas CaCO3 decomposes, why?

Among PCl3 & PF3 which is having greater bond angle and why?

CO2 has got dipole moment of zero why?

The solubility of the hydroxides of the alkaline earth metals increases i.e. Ba(OH)2 has got a higher solubility in water compared to Mg(OH)2?

The melting point of KCl is higher than that of AgCl though the crystal radii of Ag+ and K+ ions are almost same.Why?

Out of H2O and H2S which is having greater bond angle and why?

Explain why the bond angle of H2O is 104° while that that of F2O is 102°?

Why bond angle in NH3 is 107° while in H2O it is 104.5°. Though the central atom in both the molecules is sp3 hybridized.

Why the bond angle of H–C–H in methane(CH4) is 109° 28’ while H–N–H bond angle in NH3 is 107° though both carbon and nitrogen are sp3 hybridized.

Classify the following bonds as ionic, polar covalent or covalent and give your answer:

(a) Si - Si bond in

(b) Si - Cl bond in

(c) Ca - F bond in CaF2

(d) N - H bond in NH3

Calculate the minimum and maximum number of electrons which may have magnetic quantum number, m = +1 and spin quantum number s = - 1/2 in chromium(Cr):

Graphite is a soft solid lubricant extremely difficult to smelt. The reason for this anomalous behaviour is that graphite?

Two particles of mass 4kg and 6kg are seperated by a distance of 20m they are moving towards each other under mutual force of attraction the centre of mass is

A circular disc of radius 20cm is cut from one edge of larger disc of radius 50cm the shift in centre of mass

A gas at ntp is suddenly compressed to 1/4th of its org vol if gamma is supported to be 3/2 then final pressure is

Boron compounds behave as Lewis acid because of?

it takes 2s for a sound wave to travel b/w 2 fixed points when day temp is 10deg cal if temp rise to 30 deg cal sound wave travels b/w same fixed points