41.

The average power dissipated in a pure inductor is

• $\frac{{\mathrm{Vl}}^2}{4}$

• $\frac{1}{2} \mathrm{Vl}$

• Zero

• Vl²

Amplitude modulation has

• one carrier with infinite frequencies

• one carrier with two side band frequencies

• one carrier with high frequency

• one carrier

An LED is constructed from a p-n junction based on a certain semi-conducting material whose energy gap is 1.9 eV. Then, the wavelength of the emitted light is

• 6.5 × 10^-7 m

• 2.9 × 10^-9 m

• 9.1 × 10^-5 m

• 1.6 × 10^-8 m

The waves used for Line-of-Sight (LOS) communication is

• sound waves

• ground waves

• sky waves

• space waves

The given truth table is for

• NAND gate

• AND gate

• NOR gate

• OR gate

The input characteristics of a transistor in CE mode is the graph obtained by plotting

• I_B against I_C at constant V_CE

• I_B against V_BE at constant V_CE

• I_B against I_C at constant V_BE

• I_B against V_CE at constant V_BE

In a Young's double slit experiment, the slit separation is 0.5 mm and the screen is 0.5 m from the slits. For a monochromatic light of wavelength 500 nm, the distance of 3rd maxima from 2nd minima on the other side of central maxima is

• 22.5 mm

• 2.75 mm

• 2.25 mm

• 2.5 mm

Calculate the focal length of a reading glass of a person if the distance of distinct vision is 75 cm.

• 75.2 cm

• 25.6 cm

• 100.4 cm

• 37.5 cm

A person wants a real image of his own, 3 times enlarged. Where should he stand infront of a concave mirror of radius of curvature of 30 cm ?

• − 90 cm

• − 10 cm

• − 20 cm

• − 30 cm

If ε₀ and µ₀ are the permittivity and permeability of free space and ε and μ are the corresponding quantities for a medium. Then, refractive index of the medium is

• 1

• $\sqrt{\frac{{\mathrm{\mu }}_0{\mathrm{\epsilon }}_0}{\mathrm{\mu \epsilon }}}$

• insufficient information

• $\sqrt{\frac{\mathrm{\mu \epsilon }}{{\mathrm{\mu }}_0{\mathrm{\epsilon }}_0}}$