List of top Physics Questions asked in KEAM

Pick out the INCORRECT statement from the following
In a transmitter the audio signal of frequency $ω_m$ is modulated by the carrier signal $ω_c$ and the band pass filter in it rejects the frequencies
The compound semiconductor used for making LEDs of different colours is
In a CB mode of a transistor the current through the emitter is 6 mA. If the current gain of the transistor is 0.95 then its base current is
transistor
Eddy currents are not used in the applicalion of
The electric potential \(V\) at any point \((x,y,z)\) in space is given by \(V=4xz^2\) volt, where \(x,y,z\) are all in metre. The electric field at that point \((1\text{ m},0,2\text{ m})\) in \(\text{V m}^{-1}\) is
The gates that give output \(Y=0\) for the two inputs \(A=1\) and \(B=1\) are
The maximum line-of-sight distance \(d\) between the transmitting antenna of height \(h_t\) and receiving antenna of height \(h_r\) in LOS communication is \((R=\) radius of the earth\()\)
In amplitude modulation of audio frequency \(700\) Hz, the appropriate carrier frequency to be used is
If the Ge diode in the circuit is reverse biased, the current through \(2\ \text{k}\Omega\) resistor
The ratio of the energy released by \(4\) kg of hydrogen at room temperature to the heat generated by \(23.5\) kg of \({}^{235}\text{U}\) in the nuclear reactor by fission process is (Assume energy released per fusion is \(26\) MeV and that per fission is \(200\) MeV)
The contribution to the total current in a semiconductor, due to electrons and holes are \(0.75\) and \(0.25\) respectively. The drift velocity of electrons is \(\dfrac{3}{2}\) times that of holes at this temperature. Then the ratio between electron concentration and hole concentration is
In a common emitter amplifier, the input resistance and output resistance are \(200\ \Omega\) and \(50\ \text{k}\Omega\) respectively. If the voltage gain of the amplifier is \(50\), then the power gain is
A nucleus, initially at rest, breaks up into two nuclear fragments with their radii in the ratio \(2:1\). Then their velocities will be in the ratio
A certain prism produces a minimum deviation of \(42^\circ\). It produces a deviation of \(45^\circ\) when the angle of incidence is either \(43^\circ\) or \(62^\circ\). The angle of incidence when the prism undergoes minimum deviation is
The reflected ray is completely polarized for certain angle of incidence in a transparent medium. If the angle of refraction is \(30^\circ\), then the refractive index of the medium is
If two waves of intensities \(I\) and \(4I\) superpose, the ratio between maximum and minimum intensities is
The relation between the charge flow \(\Delta Q\) through the circuit of resistance \(r\) and the change in the magnetic flux \(\Delta \phi_B\) is
If an electromagnetic wave of frequency \(5\) MHz travels from vacuum into a dielectric medium of electric permittivity \(\varepsilon_r=4\), then its
Among the following, which is not true for ultraviolet light?
Choose the wrong statement.
Angular width of the first minimum on either side of the central maximum due to a single slit of width \(a\), illuminated by a light of wavelength \(\lambda\) is
A train is running at a speed of \(72\ \text{km h}^{-1}\) on the rails separated by a distance of \(150\) cm. If the vertical component of earth's magnetic field at the place is \(4.0\times10^{-5}\) T. The induced emf on the rails is
Choose the wrong statement for the pure inductive circuit.
Choose the wrong statement.