For the reaction 
are positive. The most favourable conditions for the reaction is
The ratio of closed packed atoms to tetrahedral holes in cubic close packing is
In a crystal some ions are missing from normal sites. This is an example of
The radius of Ag+ ion is 126 pm while that of I– ion is 216 pm. The coordination number of Ag+ in AgI is
The melting point of RbBr is 628°C, while that of NaF is 988°C. The principal reason that melting point of NaF is much higher than that of RbBr is that
The ionisation energy of solid NaCl is 180 kcal/mol. The dissolution of the solid in water is endothermic to the extent of 1 kcal per mol. If the solvation energies of Na+ and Cl– ions are in the ratio 6:5, what is the enthalpy of hydration of sodium ion
At 88°C benzene has a vapour pressure of 900 torr and toluene has a vapour pressure of 360 torr. What is the mole fraction of benzene in mixture with toluene that will boil at 88°C at 1 atm pressure assuming ideal solution.
When mercuric iodide is added to the aqueous solution of KI then the
Salts of A (atomic weight 7), B (atomic weight = 27) and C (atomic weight 48) were electrolysed under identical conditions using same quantity of electricity. It was found that when 2.1g of A was deposited, weights of B and C deposited were 2.7g and 7.2g. The valencies of A, B and C are respectively.
On moving a charge of 20 coulomb by 2 cm, 2 J of work is done, then what will be the potential difference between the points?
A charged ball B hangs from a silk thread S, which makes an 
with a large charged conducting sheet P, as shown in the figure. The surface charge density 
of the sheet is proportional to
Four charges equal to –Q are placed at the four corners of a square and a charge q is at its centre. What is the value of q If the system is in equilibrium?
A charged particle q is shot towards another charged particle Q which is fixed, with a speed v. It approaches Q upto a closest distance r and then returns. If q were given a speed 2v, what will b the closest distances of approach?
Two spherical conductors B and C having equal radii and carrying equal charges in them repel each other with a force F when kept apart at some distance. A third spherical conductor having the same radius as that of B but uncharged is brought in contact with B, then brought in contact with C and finally removed away from both. The new force of repulsion between B and C is
Three charges –q1, +q2 and –q3 are placed as shown in the figure. The x-component of the force on –q1 is proportional to
What is the work done in placing a charge of 8 × 10-18 coulomb on a condenser of capacity 100 micro-farad?
A thin spherical conducting shell of radius R has a charge q. Another charge Q is placed at the centre of the shell. The electrostatic potential at a point P at a distance R/2 from the centre of the shell is
A sheet of aluminum foil of negligible thickness is introduced between the plates of a capacitor. The capacitance of the capacitor
If Ihe electric flux entering and leaving an enclosed surface respectively is 
the electric charge inside the surface will be
What is capacitance (in F) of a spherical conductor with radius 1 meter?
If a charge q is placed at the centre of the line joining two equal charges Q such that the system is in equilibrium then what will be the value of q?
If there are n capacitors in parallel connected to V volt source, then the energy stored is equal to
If there are n capacitors in parallel connected to V volt source, then the energy stored is equal to
A charged particle q is placed at the centre O of cube of length L (ABCDEFGH). Another same charge q is placed at a distance L from O. Then the electric flux through ABCD is
The equations 5x2 + 12x + 13 = 0 and ax2 + bx + c = 0 (a,b,c belongs R) have a common root, where a, b, c are the sides of the 
ABC. Then find C .
The value of the expression 
will be positive for all real x if
The minimum value of the expression 4x2 + 2x + 1 is ?
Find all possible values of a for which exactly one root of x2 –(a+1)x + 2a = 0 lies in interval (0,3) ?
Find value of k for which one root of equation x2 – (k+1)x + k2 + k – 8 = 0 exceeds 2 & other is less than 2.
If q, r, s are positive, show that the equation ƒ (x) = x4 + qx2 + rx – s = 0 has one positive, one negative and two imaginary roots.
What kind of assisted reproductive technology should be prescribed if the male partner of a couple has very low sperm count?
What is the function of combined contraceptive pills?
What is the permanent methods of birth control in male and female?
Explain the steps in seed formation after a double fertilization in angiosperm.
Why the event of fertilisation in angiosperms is called double fertilisation?
Describe the sequence and process of oogenesis in schematic representation in humen female
When fetal ejection reflex pccurs> Explain the roles of diiferent hormones during parturition.
How does the placenta develop in human female?
Pollen grains are used as food supplements. explain with reason.
Ornithophilous flowers are usually bright in colour. explain with reason.
Pollen grains of anemophilous flowers are light,small and winged and are Produced in large numbers.
State the significance of parthenogenesis
How subaerial stems help in vegetative propagation?
Maize plants are monoecious and papaya plants are dioecious.Explain.
How does implantation take place in uterine wall?
Identify the given figure and describe the part labelled 'A' and 'B in it'
Pollen -pistil interaction is a safety measure to ensure that illegitimate crossing do not occur . Explain.
what is semen? give its properties and function.
Briefly describe the accessory glands in human male reproductive system.
State three contrivances to ensure autogamy.
How cleistogamous flowers are different from chasmogamous flowers?