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 *–q _{1}, +q_{2} *and

*–q*are placed as shown in the figure. The

_{3}*x-*component of the force on

*–q*is proportional to

_{1}

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?

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