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

In Young's double slit experiment, show that:

`β = (λ"D")/"d"`

Where the terms have their usual meaning.

Calculate the energy released in the following nuclear fusion reaction:

\[\ce{^2_1H + ^2_1H -> ^4_2He + energy}\]

Mass of \[\ce{^2_1H = 2.014102 u}\]

Mass of \[\ce{^4_2He = 4.002604 u}\]

In Young’s double slit experiment, how is interference pattern affected when the following changes are made:

1. Slits are brought closer to each other.
2. Screen is moved away from the slits.
3. Red coloured light is replaced with blue coloured light.

Find the energy released during the following fission reaction.

\[\ce{_92^235U + _0^1n-> _92^236U->_36^90Kr + _56^143Ba + 3 _0^1n}\]

A coil of self-inductance 2.5H and resistance 20Ω is connected to a battery of emf 120V having the internal resistance of 5 n. Find:

1) The time constant of the circuit.

2) The current in the circuit in steady state

The intensity of the electric field at a point at a perpendicular distance ‘r’ from an infinite line charge, having linear charge density ‘λ’ is given by:

A charged oil drop weighing 1.6 x 10^-15 N is found to remain suspended in a uniform electric field of intensity 2 x 10³ Nc^-1. Find the charge on the drop. 

In case of an infinite line charge, how does intensity of electric field at a point change, if at all, when.

1. charge on it is doubled?
2. distance of the point is halved?

Draw solar cell V-I characteristics.

With reference to Semiconductor Physics,

Name the process that causes depletion region in a p-n junction.

Explain photodiode.

What is the magnitude of the potential barrier across a Ge p-n junction?

What energy conversion takes place in a solar cell?

Define coherent sources of light

The intensity of the electric field at a perpendicular distance of 0·5 m from an infinitely long line charge having linear charge density (λ) is 3-6 × 10³ Vm^-1. Find the value of λ.

What is meant by coherent sources of light?

Using Ampere's circuital law, obtain an expression for the magnetic flux density 'B' at a point 'X' at a perpendicular distance 'r' from a long current-carrying conductor.
(Statement of the law is not required).

Using Ampere’s circuital law, obtain an expression for magnetic flux density ‘B’ at a point near an infinitely long and straight conductor, carrying a current I.

When current flowing through a solenoid decreases from 5A to 0 in 20 milliseconds, an emf of 500V is induced in it.

1. What is this phenomenon called?
2. Calculate coefficient of self-inductance of the solenoid.

A short electric dipole (which consists of two point charges, +q and -q) is placed at the centre 0 and inside a large cube (ABCDEFGH) of length L, as shown in Figure 1. The electric flux, emanating through the cube is:

a) `q"/"4piin_9L`

b) zero

c) `q"/"2piin_0L`

d) `q"/"3piin_0L`