A light emitting diode (LED) is fabricated using GaAs semiconducting material whose band gap is $$1.42\mathrm{eV}$$. The wavelength of light emitted from the LED is :

The value of net resistance of the network as shown in the given figure is :

Which of the diode circuit shows correct biasing used for the measurement of dynamic resistance of p-n junction diode :

Identify the logic gate given in the circuit :

The output $$\mathrm{Y}$$ of following circuit for given inputs is :

Following gates section is connected in a complete suitable circuit. For which of the following combination, bulb will glow (ON) :

The output (Y) of logic circuit given below is 0 only when :

The acceptor level of a p-type semiconductor is $$6\mathrm{eV}$$. The maximum wavelength of light which can create a hole would be : Given $$\mathrm{hc}=1242\mathrm{eV}\mathrm{nm}$$.

The correct truth table for the following logic circuit is :

A simple pendulum of length $1\mathrm{m}$ has a wooden bob of mass $1\mathrm{kg}$. It is struck by a bullet of mass $10^{-2}\mathrm{kg}$ moving with a speed of $2\times 10^2{\mathrm{ms}}^{-1}$. The bullet gets embedded into the bob. The height to which the bob rises before swinging back is. (use $\mathrm{g}=10\mathrm{m}/{\mathrm{s}}^2$ )

The bob of a pendulum was released from a horizontal position. The length of the pendulum is $$10\mathrm{m}$$. If it dissipates $$10\%$$ of its initial energy against air resistance, the speed with which the bob arrives at the lowest point is: [Use, $$\mathrm{g}:10{\mathrm{ms}}^{-2}$$]

In simple harmonic motion, the total mechanical energy of given system is $$E$$. If mass of oscillating particle $$P$$ is doubled then the new energy of the system for same amplitude is:

A simple pendulum doing small oscillations at a place $$R$$ height above earth surface has time period of $$T_1=4\mathrm{s}$$. $${\mathrm{T}}_2$$ would be it's time period if it is brought to a point which is at a height $$2\mathrm{R}$$ from earth surface. Choose the correct relation [$$\mathrm{R}=$$ radius of earth] :

If frequency of electromagnetic wave is $60\mathrm{MHz}$ and it travels in air along $z$ direction then the corresponding electric and magnetic field vectors will be mutually perpendicular to each other and the wavelength of the wave (in $\mathrm{m}$ ) is :

A plane electromagnetic wave propagating in $$\mathrm{x}$$-direction is described by $$E_y=\left(200{\mathrm{Vm}}^{-1}\right)\sin \left[1.5\times 10^{7}t-0.05x\right]\text{; }$$ The intensity of the wave is : (Use $${ϵ}_0=8.85\times 10^{-12}{\mathrm{C}}^2{\mathrm{N}}^{-1}{\mathrm{m}}^{-2}$$)

An object is placed in a medium of refractive index 3 . An electromagnetic wave of intensity $$6\times 10^8\mathrm{W}/{\mathrm{m}}^2$$ falls normally on the object and it is absorbed completely. The radiation pressure on the object would be (speed of light in free space $$=3\times 10^8\mathrm{m}/\mathrm{s}$$ ) :

Given below are two statements: Statement I: Electromagnetic waves carry energy as they travel through space and this energy is equally shared by the electric and magnetic fields. Statement II: When electromagnetic waves strike a surface, a pressure is exerted on the surface. In the light of the above statements, choose the most appropriate answer from the options given below:

In a plane EM wave, the electric field oscillates sinusoidally at a frequency of $$5\times 10^{10}\mathrm{Hz}$$ and an amplitude of $$50{\mathrm{Vm}}^{-1}$$. The total average energy density of the electromagnetic field of the wave is : [Use $${\epsilon }_0=8.85\times 10^{-12}{\mathrm{C}}^2/{\mathrm{Nm}}^2$$ ]

A plane electromagnetic wave of frequency $$35\mathrm{MHz}$$ travels in free space along the $$X$$-direction. At a particular point (in space and time) $$\vec{E}=9.6\hat{j}\mathrm{V}/\mathrm{m}$$. The value of magnetic field at this point is :

The electric field of an electromagnetic wave in free space is represented as $$\overrightarrow{\mathrm{E}}={\mathrm{E}}_0\cos (\omega \mathrm{t}-\mathrm{kz})\hat{i}$$. The corresponding magnetic induction vector will be :