Electric Charges and Fields — Physics STD 12 Science — Question

Write two definitions of mutual inductance. State what it depends on and state its unit and dimensional formula.

The phenomenon of diffraction is commonly seen in sound waves. But generally not in light waves, why?

What kind of ferromagnetic material is used for coating magnetic tapes in a cassette player or for building memory stores in a modern computer?

The susceptibility of annealed iron at saturation is 5500. Find the permeability of annealed iron at saturation.

Ultrasonic waves of frequency 4.5MHz are used to detect tumour in soft tissues. The speed of sound in tissue is 1.5km/s and that in air is 340m/s. Find the wavelength of this ultrasonic wave in air and in tissue.

A galvanometer has a resistance of 30Ω. It gives full scale deflection with a current of 2 mA. Calculate the value of the resistance needed to convert it into an ammeter of range 0-0.3 A.

The ground state energy of hydrogen atom is –13.6 eV. What are the kinetic and potential energies of the electron in this state?

Answer the following questions: Magnifying power of a simple microscope is inversely proportional to the focal length of the lens. What then stops us from using a convex lens of smaller and smaller focal length and achieving greater and greater magnifying power?

A person can hear sound waves in the frequency range 20Hz to 20kHz. Find the minimum and the maximum wavelengths of sound that is audible to the person. The speed of sound is 360m/s.