List of top Physics Questions

A convex lens has a focal length of \(20\,cm\). An object is placed \(30\,cm\) from the lens. The image distance is

The energy of an electron in the first Bohr orbit of hydrogen atom is \(-13.6\,eV\). The energy of the electron in the third orbit is

Given below are two statements: Assertion (A): In a nuclear reactor, control rods are used to control the rate of fission reaction. Reason (R): Control rods absorb excess neutrons produced during fission. Choose the correct answer from the options given below:

Given below are two statements: Assertion (A): Electromagnetic waves can travel through vacuum. Reason (R): Electromagnetic waves consist of oscillating electric and magnetic fields. Choose the correct answer from the options given below:

A photon of wavelength \(500\,nm\) is incident on a metal surface. The energy of the photon is approximately \((h=6.63\times10^{-34}\,Js,\; c=3\times10^8\,m/s)\)

Given below are two statements: Assertion (A): In a pure inductive AC circuit, current lags voltage by \(90^\circ\). Reason (R): An inductor opposes the change in current flowing through it. Choose the correct answer from the options given below:

Two charges \(+4\,\mu C\) and \(+9\,\mu C\) are separated by a distance of \(3\,m\) in vacuum. The electrostatic force between them is \((k=9\times10^9\,Nm^2C^{-2})\)

A resistor of resistance \(20\,\Omega\) is connected across a \(10\,V\) battery. The current flowing through the resistor is

In a semiconductor, the conductivity increases with increase in temperature because

Two capacitors of capacitances \(6\,\mu F\) and \(3\,\mu F\) are connected in series across a battery. The equivalent capacitance of the combination is

Two coils have mutual inductance \(0.5\,\text{H}\). If the current in the primary coil changes at the rate of \(4\,\text{A s}^{-1}\), the induced emf in the secondary coil is

A long straight conductor carries a current of \(10\,\text{A}\). The magnetic field at a point \(20\,\text{cm}\) away from the conductor is \((\mu_0=4\pi\times10^{-7}\,\text{TmA}^{-1})\)

An object is placed \(30\,\text{cm}\) in front of a concave mirror of focal length \(20\,\text{cm}\). The image distance is

A photon has energy \(6\,\text{eV}\). The corresponding work function of a metal is \(2\,\text{eV}\). The maximum kinetic energy of the emitted photoelectron is

According to Bohr's atomic model, the angular momentum of an electron in the \(n^{\text{th}}\) orbit is

In an AC circuit containing a pure resistor, the phase difference between voltage and current is

A galvanometer of resistance \(50\,\Omega\) gives full-scale deflection when a current of \(2\,\text{mA}\) passes through it. The value of shunt resistance required to convert it into an ammeter of range \(2\,\text{A}\) is

Two capacitors of capacitances \(6\,\mu F\) and \(3\,\mu F\) are connected in series across a battery. The equivalent capacitance of the combination is

In a semiconductor, the conductivity increases with increase in temperature because

An object is placed \(30\,\text{cm}\) in front of a concave mirror of focal length \(20\,\text{cm}\). The image distance is

A long straight conductor carries a current of \(10\,\text{A}\). The magnetic field at a point \(20\,\text{cm}\) away from the conductor is \((\mu_0=4\pi\times10^{-7}\,\text{TmA}^{-1})\)

A photon has energy \(6\,\text{eV}\). The corresponding work function of a metal is \(2\,\text{eV}\). The maximum kinetic energy of the emitted photoelectron is

In an AC circuit containing a pure resistor, the phase difference between voltage and current is

According to Bohr's atomic model, the angular momentum of an electron in the \(n^{\text{th}}\) orbit is