List of practice Questions

A body of mass $ 2\,kg $ is thrown up vertically with kinetic energy of $ 490\,J $ . If $ g=9.8\,m/s^{2} $ , the height at which the kinetic energy of the body becomes half of the original value, is
The apparent weight of a person inside a lift is $ w_{1}$ when lift moves up with a certain acceleration and is $ w_{2}$ when lift moves down with same acceleration. The weight of the person when lift moves up with constant speed is
If force $ (F) $ , work $ (W) $ and velocity $ (V) $ are taken as fundamental quantities, then the dimensional formula of time $ (T) $ is
In Ramsden eye-piece the focal length of each lens is $F$ . The distance of the image formed by the objective lens from the eye lens is
A body is thrown vertically up with certain initial velocity. The potential and kinetic energies of the body are equal at a point $P$ in its path. If the same body is thrown with double the velocity upwards, the ratio of potential and kinetic energies of the body when it crosses the same point, is
The source is at some distance from an obstacle. Distance between obstacle and the point of observation is $b$ and wavelength of light is $\lambda$. Then the average distance of nth Fresnel zone will be at a distance from the point of observation
What is the value of inductance L for which the current is a maximum in a series LCR circuit with $ C=10\,\mu F $ and $ \omega =1000\,{{s}^{-1}} $ ?
The maximum number of possible interference maxima for slit-separation equal to twice the wavelength in Youngs double-slit experiment, is
A ball is thrown from a point with a speed $ {{v}_{0}} $ at an angle of projection $ \theta $ . From the same point and at the same instant, a person starts running with a constant speed $ \frac{{{v}_{0}}}{2} $ to catch the ball. Will the person be able to catch the ball If yes, what should be the angle of projection?
Spherical balls of radius R are falling in a viscous fluid of viscosity n with a velocity v. The retarding viscous force acting on the spherical ball is
In radioactive decay process, the negatively charged emitted $ \text{-} $ particles are
The binding energy of deuteron is $2.2 \,MeV$ and that of $ _{2}^{4}He$ is $28 \,MeV$. If two deuterons are fused to form one $ _{2}^{4} He$, then the energy released is
A transistor-oscillator using a resonant circuit with an inductor $L$ (of negligible resistance) and a capacitor $C$ in series produce oscillations of frequency $ f $ . If $L$ is doubled and $C$ is changed to $4C$, the frequency will be
A Carnot engine whose sink is at $300 \,K$ has an efficiency of $40\%$. By how much should the temperature of source be increased so as to increase its efficiency by $50\%$ of original efficiency?
Two masses $ m_{1}=5\,kg $ and $ m_{2}=4.8\,kg $ tied to a string are hanging over a light frictionless pulley. What is the acceleration of the masses when lift is free to move ? $ (g=9.8 \, m/s^{2}) $
Two cells, having the same emf, are connected in series through an external resistance $R$. Cells have internal resistances $ r_{1} $ and $ r_{2} $ $ (r_{1} > r_{2}), $ respectively. When the circuit is closed, the potential difference across the first cell is zero. The value of $R$ is
A black body at $ 1227^{\circ} C $ emits radiations with maximum intensity at a wavelength of $ 5000\,? $ . If the temperature of the body is increased by $ 1000^{\circ} C $ , the maximum intensity will be observed at
The radius of a spherical drop of water is $1 \,mm$. If surface tension of water be $70\times10^{-3} Nm^{-1},$ the pressure difference inside and outside the drop will be
The earth is assumed to be a sphere of radius $R$. A platform is arranged at a height $R$ from the surface of the earth. The escape velocity of a body from this platform is $fv$, where $v$ is its escape velocity from the surface of the Earth. The value of $f$ is :-
Which of the following units denotes the dimensions $\frac {ML^{2}} {Q^{2}},$ where $Q$ denotes the electric charge ?
A string is stretched between fixed points separated by 75.0 cm. It is observed to have resonant frequencies of 420 Hz and 315 Hz. There are no other resonant frequencies between these two. Then, the lowest resonant frequency for this string is :
In a common-base mode of a transistor, the collector current is 5.488 mA for an emitter current of 5.60 mA. The value of the base current amplification factor $\left(\beta\right)$ will be :
A particle of mass 100 g is thrown vertically upwards with a speed of 5 m/s. The work done by the force of gravity during the time the particle goes up is :
Starting from the origin a body oscillates simple harmonically with a period of 2 s. After what time will its kinetic energy be 75% of the total energy ?
Assuming the sun to be a spherical body of radius R at a temperature of T K, evaluate the total radiant power, incident on earth, at a distance r from the sun : where $r_{0}$ is the radius of the earth and $\sigma$ is Stefan?s constant.