Magnetism and Matter — Physics STD 12 Science — Question

How does an increase in doping concentration affect the width of depletion layer of a p-n junction diode?

What is nuclear fusion?

A circular loop of radius 4.0cm is placed in a horizontal plane and carries an electric current of 5.0A in the clockwise direction as seen from above. Find the magnetic field:

1. At a point 3.0cm above the centre of the loop.
2. At a point 3.0cm below the centre of the loop.

At a place, the horizontal component of earth's magnetic field is B and angle of dip is 60°. What is the value of horizontal component of the earth's magnetic field at equator?

At Deoprayag (Garhwal, UP) river Alaknanda mixes with the river Bhagirathi and becomes river Ganga. Suppose Alaknanda has a width of 12m, Bhagirathi has a width of 8m and Ganga has a width of 16m. Assume that the depth of water is same in the three rivers. Let the average speed of water in Alaknanda be 20km/h and in Bhagirathi be 16km/h. Find the average speed of water in the river Ganga.

Choose the correct alternative from the clues given at the end of the each statement:
A classical atom based on .......... is doomed to collapse. (Thomson’s model/ Rutherford’s model.)

If the magnetic field outside a copper box is suddenly changed, what happens to the magnetic field inside the box? Such low-resistivity metals are used to form enclosures which shield objects inside them against varying magnetic fields.

If the rate of change of current 2 ampere/ second induces an emf of 40 mV in the solenoid, what is the self-inductance of this solenoid?