List of top Physics Questions

Two identical cells gave the same current through an external resistance of \( 2 \)$\omega$ regardless of whether the cells are grouped in series or parallel. The internal resistance of the cells is:
Three rings, each with equal radius \( r \), are placed mutually perpendicular to each other and each having centre at the origin of the coordinate system. If \( I \) is the current passing through each ring, the magnetic field value at the common centre is:
Three rings, each with equal radius
A 50 Hz AC circuit has a 10 mH inductor and a 2 $\omega$ resistor in series. The value of capacitance to be placed in series in the circuit to make the circuit power factor unity is:
The structure of solids is investigated by using:
The surface of a metal is first illuminated with a light of wavelength 300 nm and later illuminated by another light of wavelength 500 nm. It is observed that the ratio of maximum velocities of photoelectrons in two cases is 3. The work function of the metal value is close to:
The ratio of the minimum wavelength of the Balmer series to the maximum wavelength in the Brackett series in the hydrogen spectrum is:
The half-life period of a radioactive element A is 62 years. It decays into another stable element B. An archaeologist found a sample in which A and B are in 1 : 15 ratio. The age of the sample is:
A block of mass 18.5 kg kept on a smooth horizontal surface is pulled by a rope of 3 m length by a horizontal force of 40 N applied to the other end of the rope. If the linear density of the rope is 0.5 kgm\(^-1\) and initially the block is at rest, the time in which the block moves a distance of 9 m is

A man of mass 70 kg jumps to a height of 0.8 m from the ground, then the momentum transferred by the ground to the man is 
(g = 10 m/s\(^{-2}\)):

In the given circuit, the potential difference across the 5 \(\mu\)F capacitor is 

Three particles of each mass \( m \) are kept at the three vertices of an equilateral triangle of side \( 1 \). The moment of inertia of the system of the particles about any side of the triangle is:
If the work done \(W\), length \(L\) and time \(T\) are considered as the fundamental quantities, the dimensional formula for mass is:
The relation between the force (F in newton) acting on a particle executing simple harmonic motion and the displacement of the particle (y in metre) is given by: \[ 500F + \pi^2 y = 0 \] If the mass of the particle is 2 g, the time period of oscillation of the particle is:
The RMS value of the electric field of an electromagnetic wave emitted by a source is \( 660 \) N/C. The average energy density of the electromagnetic wave is:
The focal length of double concave lens having refractive index 1.5 kept in air with two spherical surfaces of radii \( R_1 = 20 \, \text{cm} \) and \( R_2 = 80 \, \text{cm} \) is
The focal length of a lens having power 4D is
The magnetic force exerted on a 3 m length conductor carrying 2A current when placed in a uniform magnetic field 0.4 T at an angle 30° is
The focal length of a concave mirror is 20 cm. At what distance the object is placed to obtain the virtual image?
The defect in eye vision that people cannot see objects at long distance is

A metal rod of 50 cm length is clamped at its midpoint and is set to vibrations. The density of that metal is \( 2 \times 10^3 \, {kg/m}^3 \).
Young's modulus of that metal is \( 8 \times 10^8 \, {Nm}^2 \). The fundamental frequency of the vibration is 
 

The tangent drawn to the magnetic field line at a point gives
Two masses \( m_1 \) and \( m_2 \) are connected by a light string passing over a smooth pulley. When set free, \( m_1 \) moves downwards by 3 m in 3 s. The ratio of \( \frac{m_1}{m_2} \) is \((g = 10 \text{ m/s}^2)\).

A hydrogen atom falls from nth higher energy orbit to first energy orbit (n = 1). 

The energy released is equal to 12.75 eV. The nth orbit is

The longest wavelength of light that can initiate photo electric effect in the metal of work function 9 eV is
Magnetic field at a distance \(r\) from z axis is \( B = B_0 r \, \text{kt} \) present in the region. \( B_0 \) is constant and \(t\) is time. The magnitude of induced electric field at a distance \(r\) from z-axis is.