List of top Physics Questions

Water rises in a capillary tube to a height \(h\). Choose false statement regarding capillary rise from the following.

Force between two identical charges placed at a distance of \(r\) in vacuum is \(F\). Now a slab of dielectric of dielectric constant 4 is inserted between the charges. If the thickness of the slab is \(r/2\), then the force between the charges will become

Two identical cells whether connected in parallel or in series gives the same current when connected to an external resistance 1.5 \(\Omega\). Find the value of internal resistance of each cell.

Three blocks of masses \(m_1\), \(m_2\) and \(m_3\) are connected by massless strings as shown on a frictionless table. They are pulled with a force \(T_3 = 40\) N. If \(m_1 = 10\) kg, \(m_2 = 6\) kg and \(m_3 = 4\) kg, the tension \(T_2\) will be}

A string of density \(7.5\) g cm\(^{-3}\) and area of cross-section \(0.2\) mm\(^2\) is stretched under a tension of 20 N. When it is plucked at the mid-point, the speed of the transverse wave on the wire is

Two identical air core capacitors are connected in series to a voltage source of 15 V. If one of the capacitors is filled with a medium of dielectric constant 4, the new potential across this capacitor is

Eight grams of Cu$^{66}$ undergoes radioactive decay and after 15 minutes only 1 g remains. The half-life, in minutes, is then}

A torque of $1$ N m is applied to a wheel which is at rest. After $2$ seconds the angular momentum in kg m$^2$/s is

A wheel rotating at $12$ rev/s is brought to rest in $6$ s. The average angular deceleration in rad/s$^2$ of the wheel during this process is

For a light nuclei, which of the following relation between the atomic number (Z) and mass number (A) is valid

If the rms value of sinusoidal input to a full wave rectifier is $V_0/\sqrt{2}$ then the rms value of the rectifier’s output is}

Consider a circular wire loop of radius R spinning about a diametrical chord which is perpendicular to a uniform magnetic field $(\vec{B}=B_0 \hat{k})$

If a magnet is dropped through a vertical hollow copper tube then

An electric motor when loaded has an effective resistance of $30\,\Omega$ and an inductive reactance of $40\,\Omega$. If the motor is powered by a source with maximum voltage of $420\,V$, the maximum current is

Which of the following particle when bombards on $^{65}\text{Cu}$ will turn into $^{66}\text{Cu}$}

CO$^{-}$ ion moving with kinetic energy of 20 keV dissociates into O$^{-}$ and C which move along the parent ion direction. Assuming no energy is released during dissociation, the kinetic energies of the daughters $(K.E.)_{O^-}$ and $(K.E.)_C$ are related as}

Wavelength of the wave with $30$ MHz frequency is

Speech signal is in the range of

To transmit a signal of frequency, $\omega_m$, with a carrier frequency, $\omega_c$, in AM transmission, the bandwidth of the filter and amplifier is

For a P-N junction diode

For a Zener diode

In an insulator, band gap is of the order of

The electric field portion of an electromagnetic wave is given by (all variables in SI units) $E = 10^{-4} \sin (6 \times 10^5 t - 0.01 x)$. The frequency $(f)$ and the speed $(v)$ of electromagnetic wave are}

It takes $4.6$ eV to remove one of the least tightly bound electrons from a metal surface. When monochromatic photons strike the metal surface, electrons having kinetic energy from zero to $2.2$ eV are ejected. What is the energy of the incident photons?

An electron, a neutron and an alpha particle have same kinetic energy and their de-Broglie wavelengths are $\lambda_e, \lambda_n$ and $\lambda_\alpha$ respectively. Which statement is correct about their de-Broglie wavelengths?