List of practice Questions

A body floats in a liquid contained in a beaker. If the whole system as shown in figure falls freely under gravity, then the upthrust on the body due to liquid is
If one of the lines of $my^2 + (1 - m^2)xy - mx^2 = 0$ is a bisector of the angle between the lines $xy = 0$, then $m$ is
A current of $4.8\, A$ is flowing in a conductor. The number of electrons passing per sec through the conductor will be
Bakelite is obtained from phenol by reaction with
A coin is dropped in a lift. It takes time $t_1$ to reach the floor when lift is stationary. It takes time $t_2$ when lift is moving up with constant acceleration. Then
A circular disc of radius $R$ is removed from a bigger circular disc of radius $2R$, such that the circumferences of the discs coincide. The centre of mass of the new disc is $\alpha/R$ from the centre of the bigger disc. The value of $\alpha$ is
A child is swinging a swing. Minimum and maximum heights of swing from earth's surface are $0.75\, m$ and $2 \,m$ respectively. The maximum velocity of this swing is
A cell swells up when kept in
The radius of germanium (Ge) nuclide is measured to be twice the radius of $_{4}^{9}Be.$ The number of nucieons in Ge are
An arrow is shot into air. Its range is 200 m and its time of flight is 5 s. If g = 10 $ ms^{- 2} $, then the horizontal component of velocity of the arrow is
A laser beam is coherent because it contains
When a triode valve is used as an amplifier the phase difference between input and output voltages is
A cosmonaut is orbiting earth in a spacecraft at an altitude h = 630 km with a speed of 8 k$ms^{ - 1}$. If the radius of the earth is 6400 km, the acceleration of the cosmonaut is
A car runs at a constant speed on a circular track of radius 100 m, taking 62.8 s for every circular lap. The average velocity and average speed for each circular lap respectively is
How should people wearing spectacles work with a microscope?
A 5 A fuse wire can withstand a maximum power of 1 W in circuit. The resistance of the fuse wire is
When a body is in resonance following physical quantity gradually increases?
Two bodies of different masses are dropped from a tower, assuming that air resistance is proportional to the mass of body. Which of the following is correct?
A man will weigh more when
Find equivalent capacitance between $A$ and $B$
Path of cathode rays entering uniform magnetic field normal to the field
The energy of an electron in an excited hydrogen atom is $ -3.4\,eV $ . Its angular momentum is
A short linear object of length $b$ lies along the axis of a concave mirror of focal length $f$ at a distance $u$ from the pole of the mirror, what is the size of image?
The difference between the apparent frequency of a source of sound as perceived by the observer during its approach and recession is $2\%$ of the frequency of the source. If the speed of sound in air is $ 300\,ms^{-1}$ , the velocity of the source is
A count rate metre shows a count of $240/\min$ from a given radioactive source later the metre shows a count rate of $30/\min$. The half-life of the source is