List of practice Questions

A carbon resistor is marked with the ring coloured brown, black, green and gold. The resistance in ohm is
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 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 $R \,= \,6400 \,km$)
A linear harmonic oscillator with force constant 3.210N m and amplitude 0.01 m has a
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
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
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 : $k = \frac{1}{4 \pi \varepsilon_0}$]
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 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 change in potential of the half-cell $Cu^{2+}|Cu$, when aqueous $Cu^{2+}$ solution is diluted $100$ times at $298 \,K$ ? $\left( \frac{2.303 RT}{F} = 0.06 \right)$
The current $ I $ through $ 10\,\Omega $ resistor in the circuit given below is
The dimensional formula for rate of doing work is
The number of lone pair and bond pair of electrons on the sulphur atom in sulphur dioxide molecule are respectively
The phase velocity of a wave described by the equation $\Psi = \Psi_0 \, \sin (kx + \omega t + \pi / 2)$ is
The polarity of induced emf is given by
The standard electrode potentials of $ A{{g}^{+}}/Ag $ is $ +0.80\text{ }V $ and $ C{{u}^{+}}/Cu $ is $ +0.34\text{ }V $ . These electrodes are connected through a salt bridge and if:
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
A bullet fired into a fixed wooden block loses half of its velocity after penetrating $40\,cm$. It comes to rest after penetrating a further distance of
A cyclist bends while taking turn in order to
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 paramagnetic substance of susceptibility $ 3\times {{10}^{-4}} $ is placed in a magnetic field of $ 4\times {{10}^{-4}}A{{m}^{-1}} $ . Then the intensity of .magnetization in the units of $ A{{m}^{-1}} $ 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 rubber cord of density $d,$ Young?s modulus $Y$ and length $L$ is suspended vertically. If the cord extends by a length $0.5\, L$ under its own weight, then $L$ is
A small spherical ball falling through a viscous medium of negligible density has terminal velocity $v$. Another ball of the same mass but of radius twice that of the earlier falling through the same viscous medium will have terminal velocity
Aluminium (atomic mass = $27$) crystallizes in a cubic system with edge length of $4 \, ?$. Its density is $2.7 \,g \,cm^{-3}$. The number of aluminium atoms present per unit cell is