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?

How Does Simple polyembryony differ from adventive polyembryony?

What is the significance of apomixis?

How are sexually transmitted diseases spread?give example of any two STDs with their causative agents.

A veery useful strategy for detecting disorder in developing embryo is now under statutory ban.Give Reason.

Which area are covered by the reproduction and child helth care (RCH) Programme?

List out any four derivatives of ectoderm.

How the three germ layers formed in human embryo?

What is spermatogenesis? Which major events take place

during the following stages of formation of spermatids?

(a) Multiplication phase

(b) Growth phase

(c) Maturation phase

1 mole of gas H2 and 4 moles of gas O2 is taken inside the vessel, which effuse through a small orifice of the vessel having same area of cross section and at the same temperature, then which is the correct % of effused volume of gas H2 and O2 initially respectively? (Assume that the gas H2 does not react with O2 gas)

The term that corrects for the attractive forces present in a real gas in the van der Waals equation is

Two samples of gases A and B are at the same temperature. The molecules of A are travelling four times faster

than the molecules of B. The ratio of mA / mB

## Five molecules of a gas moving with speeds 1, 2, 3, 4, 5 km/s. What is their root mean square speed?

Five molecules of a gas moving with speeds 1, 2, 3, 4, 5 km/s. What is their root mean square speed?

The mass percent composition of dry air at sea level is given. The partial pressure of each component will be

A vertical hollow cylinder of height 152 cm is fitted with a weightless piston. The lower half is filled with an ideal gas and the upper half with mercury.The cylinder is now heated at300K,so that 1/4th of the mercury comes out.Find the temperature at which it will happen assuming thermal expansion of Hg to be negligible

A 10 cm air column is trapped inside the tube (having uniform area of cross section) by 6 cm of Hg and is placed horizontally to the plane. Calculate the length of air column when the tube is placed vertically with opened end up.

50 ml of mixture of NH3 and H2 are decomposed to yield N2 and H2 and to the resulting mixture 40 ml O2 is added and the mixture is sparked to yield H2O. When the resulting mixture of gases were passed through alkaline pyrogallol 6 ml contraction was observed. Calculate the percentage composition of NH3 in the original mixture

2 g of a gas A is introduced into an evacuated flask kept at 25°C. The pressure is found to be 1 atm. If 3 g of another gas B is added to the same flask the total pressure becomes 1.5 atm, assuming ideal gas behaviour. The ratio of molecular weight of gas A to gas B (MA : MB) is

At what temperature, the average speed of gas molecules will be double that at 27°C ?

Two identical bulbs containing ideal gases A and B are taken. Density of A is twice that of B .Mol wt. of A is half that of B.If two gases are at the same temperature, the ratio of pressure of A & B is

200 ml of He at 0.66 atm pressure and 400 ml of O2 at 0.52 atm pressure are mixed in a 400 ml vessel at 25°C. The partial pressure of He and O2 will be?

## 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

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 and B are two concentric hollow conductors having radii a and 2a and charged 2Q and Q respectively.If potential of outer sphere is 5V then potential of inner sphere is?

0.2 g of a gas X occupies a volume of 0.44 litre at given pressure and temperature. Under identical conditions of P and T, 0.1 g of CO2 gas occupies 0.32 L volume. The gas X can be

One end of a thermally insulated rod is kept at a temperature *T _{1}* and the other at

*T*The rod is composed of two sections of lengths

_{2}.*l*and

_{1}*l*and thermal conductivities

_{2}*K*and

_{1}*K*respectively. What would be the temperature at the interface of the two sections?

_{2}-0

Assuming the sun to be a spherical body of radius *R* at a temperature of *TK*, evaluate the total radiant power, incident on earth, at a distance *r* from the sun.

Note: r_{0} is the radius of the earth and is Stefan's constant.

The figure shows a system of two concentric spheres of radii *r*_{1 }and *r _{2}* and kept at temperatures

*T*

_{1 }and

*T*respectively. The radial rate of flow of heat in a substance between the two concentric spheres is proportional to

_{2},