ISC (Science) ISC Class 12 - CISCE Question Bank Solutions

Derive an expression for the intensity of electric field at a point in broadside position or on [4)
an equatorial line of an electric dipole.

Two-point charges Q₁ = 400 μC and Q₂ = 100 μC are kept fixed, 60 cm apart in a vacuum. Find the intensity of the electric field at the midpoint of the line joining Q₁ and Q₂.  

In an electric dipole, at which point is the electric potential zero ? 

Show that intensity of electric field at a point in broadside position of an electric dipole is given by:

E = `(1/(4 pi epsilon_0)) p/((r^2 + l^2)^(3//2))`

Where the terms have their usual meaning.

In an electric dipole, what is the locus of a point having zero potential?

Arrangement of an oxygen ion and two hydrogen ions in a water molecule is shown in the figure below.

Calculate the electric dipole moment of a water molecule. Express your answer in terms of e (charge on hydrogen ions), l and θ.

Write one balanced equation to show Nuclear fission

Write one balanced equation to show Nuclear fusion

Why nuclear fusion reaction is also called thermo-nuclear reaction?

Write one balanced reaction representing nuclear fusion.

In a nuclear reactor, what is the function of a moderator?

In our Nature, where is the nuclear fusion reaction taking place continuously?

A transformer is used to step up an alternating emf of 200V to 440V. If the primary coil has 1000 turns, calculate the number of turns in the secondary coil. 

An a.c generator generates an emf 'ε' where ε = 314 Sin (50πt) volt. Calculate the frequency of emf ε.

What is the turns ratio i.e., transformer ratio, n_s: n_p, in an ideal transformer which in-creases ac voltage from 220 V to 33000 V?

In an ideal transformer, an output of 66 kV is required when an input voltage of 220 V is available. If the primary has 300 turns, how many turns should the secondary have?

What is the ideal transformer? 

The primary coil of a transformer has 60 turns whereas its secondary coil has 3000 turns.

If a 220 V ac voltage is applied to the primary coil, how much emf is induced in the secondary coil?

The primary coil of a transformer has 60 turns whereas its secondary coil has 3000 turns.

If a current of 5A flows in the primary coil, how much current will flow in a load in the secondary coil? State the assumption you have made regarding the transformer, in this calculation.

What type of transformer is used in a mobile phone charger?