List of top Physics Questions on Electromagnetic waves asked in Rajasthan PMT

A metal wire of linear mass density of 9.8 g/m is stretched with a tension of 10 kg-wt between two rigid supports 1 m apart. The wire passes at its middle point between the poles of a permanent magnet and it vibrates in resonance when carrying an alternating current of frequency n. The frequency n of the alternating source is

Distance between successive compression and rarefaction is $1 \,m$ and velocity of sound is $360 \,ms^{-1}$. Find frequency :

The de-Broglie wavelength $ \lambda $ :