Materials and Components Questions

• Assertion (A): If an electron having charge e is revolving in an orbit of radius R and with angular velocity ω, the magnetic dipole moment of orbit is 0.5 eωR2. Reason (R): Orbital angular momentum and magnetic dipole moment are always equal.
• For making a capacitor it is better to have a dielectric having
• Assertion (A): The angular momentum of an atom is due to three contributions viz. orbital, electron spin and nuclear spin. Reason (R): The nuclear spin magnetic moment is much more than electron spin magnetic moment.
• In solid insulator materials having only one kind of atom, the types of polarization which exist are
• Schrodinger wave equation is a
• Above a certain temperature, the specific heat of a metal becomes constant. This temperature is called
• For magnetic shielding, we need a ferromagnetic material.
• At room temperature the number of conducting electrons in an intrinsic semiconductor
• As the viscosity of a liquid increases, the relaxation time
• If Bmax is the maximum flux density, eddy current loss is proportional to
• As per temperature limits, the number of categories of solid dielectrics are
• If the radius of electron cloud around the nucleus of a rare gas atom is R, the electronic polarizability of the atom is porportional to
• If Bmax is the maximum flux density, hysteresis loss is proportional to
• Many compounds also exhibit semiconducting properties.
• An atom of a rare gas is placed is an electric field E. Then
• Assertion (A): A capacitor with imperfect dielectric can be represented by a capacitance in parallel with resistance. Reason (R): For imperfect dielectrics, dielectric constant has real and imaginary parts.
• In a metal, the valence electrons
• The dielectric losses do not depend on frequency.
• The rule that resistivity of conductors can be separated into two parts viz. temperature independent and temperature dependent is known as
• If m is the mass of electron cloud, the equation of motion of electron cloud in the presence of an alternating electric field is of the form