Department of Physics;
Indian Institute of Technology(BHU);
Varanasi 221005;
India;
Institute of Solar-Terrestrial Physics SB RAS;
Lermontov Str.126A;
664033;
Irkutsk;
Russia;
Pulkovo Astronomical Observatory;
Pulkovskoe Sh.65;
St.Petersberg;
196140;
Russia;
magnetic field; Sun:activity; Sun:magnetic fields; stars:rotation; stars:dynamo; stars;