List of top Physics Questions

The formation of ice is started in a lake with water at $0^{\circ} C$. When the atmospheric temperature is $-10^{\circ} C$. If time taken for $1 \,cm$ of ice to be formed is $7$ hours, the time taken for the thickness of ice to increase from $1 \,cm$ to $2 \,cm$ is :
The focal length of the field lens (which is an achromatic combination of two lenses) of a telescope is $90$ cm. The dispersive powers of the two lenses in the combination are $0.024$ and $0.036$.The focal lengths of the two lenses are
Radio frequency choke has core of
The de-Broglie wavelength $ \lambda $ :
A fighter plane is moving in a vertical circle of radius $r$. Its minimum velocity at the highest point of the circle will be
Lorentz force is given by the following formula
The probability of electrons to be found in the conduction band of an intrinsic semiconductor at a finite temperature :
A string of length $ l $ fixed at one end carries a mass m at the other end. The string makes $ \frac{2}{\pi } $ rev/s around the horizontal axis through the fixed end as shown in the figure, the tension in string is :
For a transistor, in a common emitter arrangement, the alternating current gain $P$ is given by :
Between the proton and neutron in a nucleus:
Which one of the following represents the correct dimensions of the coefficient of viscosity?
When charge is given to a soap bubble, it shows:
When a body is earth connected, electrons from the earth flow into the body. This means the body is .............
$v_{rms} , v_{av}$ and $v_{mp}$ are root mean square, average and most probable speeds of molecules of a gas obeying Maxwellian velocity distribution. Which of the following statements is correct?
Two forces of $12\,N $ and $8\,N$ act upon a body. The resultant force on the body has a maximum value of :
Three particles, each of mass $m$ gram, are situated at the vertices of an equilateral triangle $ABC$ of side $l$ cm (as shown in the figure). The moment of inertia of the system about a line $AX$ perpendicular to $AB$ and in the plane of $ABC$, in $gram-cm^2$ units will be
The temperature at which ferromagnetic material becomes paramagnetic is called a
The recoil velocity of a $ 4.0\, kg $ rifle that shoots a $ 0.050\, kg $ bullet at a speed of $ 280\text{ }m{{s}^{-1}} $ is:
The pressure maintained in Coolidge tube is:
The number of bullets are fired in all possible directions with the same initial velocity $u$. The maximum area of ground covered by bullets is :
The magnetic field due to a current carrying circular loop of radius $3\, cm$ at a point on the axis at a distance of $4\, cm$ from the centre is $54 \,\mu T$. What will be its value at the centre of the loop?
The magnetic field due to a straight conductor of uniform cross-section of radius a and carrying a steady current is represented by
The energy of a photon is equal to the kinetic energy of a proton. The energy of the photon is E. Let $ \lambda_1 $ be the de-Broglie wavelength of the proton and $ \lambda_2 $ be the wavelength of the photon. The ratio $ \frac{\lambda_1}{\lambda_2} $ is proportional to
The emitter-base junction of a transistor is ............. biased while the collector-base junction is ............. biased.
The electrostatic force between two charges of $10\,\mu C$ and $20\,\mu C$ at a distance of $2m$ is to be halved. This can be effected by