COMEDK 2023 Morning Shift

An LED is constructed from a \(p\)-\(n\) junction diode using GaAsP. The energy gap is \(1.9 \mathrm{~eV}\). The wavelength of the light emitted will be equal to

The phase difference between displacement and velocity of a particle in simple harmonic motion is

The sides of a parallelogram are represented by vectors \(\vec{p}=5 \hat{\mathbf{i}}-4 \hat{\mathbf{j}}+3 \hat{\mathbf{k}}\) and \(\vec{q}=3 \hat{\mathbf{i}}+2 \hat{\mathbf{j}}-\hat{\mathbf{k}}\). Then, the area of the parallelogram is

In Young's double slit interference experiment, using two coherent waves of different amplitudes, the intensities ratio between bright and dark fringes is 3 . Then, the value of the ratio of the amplitudes of the wave that arrive there is

In Young's double slit experiment, the ratio of maximum and minimum intensities in the fringe system is \(9: 1\). The ratio of amplitudes of coherent sources is

With what velocity should an observer approach a stationary sound source, so that the apparent frequency of sound should appear double the actual frequency?

A car is moving towards a high cliff. The car driver sounds a horn of frequency \(f\). The reflected sound heard by the driver has a frequency \(2 f\). If \(v\) be the velocity of sound, then the velocity of the car in the same velocity uni...

A string vibrates with a frequency of \(200 \mathrm{~Hz}\). When its length is doubled and tension is altered, it begins to vibrate with a frequency of \(300 \mathrm{~Hz}\). The ratio of the new tension to the original tension is

A particle is projected at an angle \(30^{\circ}\) with horizontal having kinetic energy \(K\). The kinetic energy of the particle at highest point is.

A long spring, when stretched by a distance \(x\), has potential energy \(U\). On increasing the stretching to \(n x\), the potential energy of the spring will be