List of top Physics Questions asked in KEAM

The phase velocity of a wave described by the equation $\Psi = \Psi_0 \, \sin (kx + \omega t + \pi / 2)$ is
Four point charges (with equal magnitude of charge of $5\, C$; but with different signs) are placed at four corners of a square of side $10\, m.$ Assuming that the square is centered at the origin and the configuration of the charges are as given in the figure, the potential and the magnitude of electric field at the origin, respectively are [ Note : $k = \frac{1}{4 \pi \varepsilon_0}$]
The dimensional formula for rate of doing work is
The apparent frequency observed by a moving observer away from a stationary source is $20\%$ less than the actual frequency. If the velocity of sound in air is $330 \; ms^{-1}$ , then the velocity of the observer is
The polarity of induced emf is given by
A battery of $6\,V$ and internal resistance $2 \Omega$ is connected to a silver voltameter. If the current of $1.5\, A$ flows through the circuit, the resistance of the voltameter is
A carbon resistor is marked with the ring coloured brown, black, green and gold. The resistance in ohm is
An experiment measures quantities $a$, $b$ and $c$, and quantity $X$ is calculated from $X= ab^2/c^3$. If the percentage error in $a$, $b$ and $c$ are $\pm 1\%$, $\pm 3\%$ and $\pm 2\%$, respectively, then the percentage error in $X$ will be
A linear harmonic oscillator with force constant 3.210N m and amplitude 0.01 m has a
A Carnot engine is operating between a hot body and cold body maintained at temperature $T_1$ and $T_2$ respectively. Consider the following three cases : The temperature of the hot body is changed to $T_1 + \Delta T$ and cold body is at $T_2$ : The temperature of the hot body is at $T_1$ and cold body is changed to $T_2 + \Delta T$ : The temperature of the hot body is at $T_1$ and cold body is changed to $T_2 - \Delta T$
A metallic bar of coefficient of linear expansion $10^{-5} K^{-1}$ is heated from $0^{\circ}C$ to $100^{\circ}C$. The percentage increase in its length is
If $m$ represents the mass of each molecule of a gas and $T$, its absolute temperature, then the root mean square velocity of the gaseous molecule is proportional to
The current $ I $ through $ 10\,\Omega $ resistor in the circuit given below is
A ground receiver receives a signal at $5\, MHz$, transmitted by a ground transmitter at a height of $320\, m$, which is $110\, km$ away from it. Then it can communicate through (radius of earth $R \,= \,6400 \,km$)
The Carnot cycle of a reversible heat engine consists of
The power factor of $LCR$ circuit at resonance is
The propulsion of a rocket is based on the principle of conservation of
The amount of charge flowing per second per unit area normal to the flow is called
Identify the wrong statement
The number of photons emitted per second by a $60\, W$ source of monochromatic light of wavelength $663\, nm$ is $ (h=6.63\times {{10}^{-34}}Js) $
The magnification of an image by a convex lens is positive only when the object is placed
The depth $d$ at which the value of acceleration due to gravity becomes $\frac {1} { n}$ time the value at the surface is (R be the radius of the earth)
A narrow slit of width $2 \,mm$ is illuminated by monochromatic light of wavelength $500\, nm$. The distance between the first minima on either side on a screen at a distance of $1 \,m$ is
A radioactive sample at any instant has its disintegration rate $5000$ disintegrations per minute. After $5\, min$, the rate becomes $1250$ disintegration per minute. Then, its decay constant (per minute) is
A ball is dropped from a height $h$. If the coefficient of restitution is $e$ then to what height will it rise after jumping twice from the ground