List of top Physics Questions

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 block of mass 100 g is attached to the end of a string of unknown material of 50 cm long and cross-sectional area of \(2 \, {cm}^2\). When the block is whirled horizontally at a constant angular speed of 40 m/s, it moves along a circular path of radius 52 cm. Young's modulus of the material 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 radii of two conducting spheres A and B of each charge +90 µC are 8 cm and 10 cm respectively. When the two spheres are connected by a conducting wire, then the charge flowing from sphere A to sphere B 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
An electromagnetic wave travels in a medium with a speed of \( 2 \times 10^8 \, \text{ms}^{-1} \). The relative permeability of the medium is 1. Then the relative permittivity 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.
A body falling freely under gravity from rest from a certain height reaches the ground in \(5\) seconds. The distance travelled by the body in the last two seconds of its motion is:
In Young's double slit experiment light of wavelength 500 nm is used to form interference pattern. A uniform glass plate of refractive index 1.5 and thickness 0.1 mm is introduced in the path of one of the interfering beams. The number of fringes that will shift due to this is
Concave mirrors can produce
A coil of inductance 1H and resistance 100Ω is connected to an alternating current source of frequency $ \frac{50}{\pi} $ Hz. What will be the phase difference between the current and voltage?
A glass of hot water cools from 90°C to 70°C in 3 minutes when the temperature of the surroundings is 20°C. What is the time taken by the glass of hot water to cool from 60°C to 40°C if the surrounding temperature remains the same at 20°C?
The resistance of the galvanometer and shunt of an ammeter are 90 ohms and 10 ohms respectively, then the fraction of the main current passing through the galvanometer and the shunt respectively are:
If $ A $ is the areal velocity of a planet of mass $ M $, then its angular momentum is:

In amplitude modulation, the amplitude of the carrier wave is 10 V and the amplitude of one of the side bands is 2 V. The modulation index is:

The plane 𝑧=0 separates two linear dielectric media with relative permittivities 𝜀𝑟1=4 and 𝜀𝑟2=3, respectively. There is no free charge at the interface. If the electric field in the medium 1 is 𝐸⃗ 1=3𝑥̂+2𝑦̂ +4𝑧̂, then the displacement vector \(\overrightarrow{D_2}\) in medium 2 is: (𝜀0 is the permittivity of free space)
A square shaped aluminium coin weighs 0.75 g and its diagonal measures 14 mm. It has equal amounts of positive and negative charges. Suppose those equal charges were concentrated in two charges (+Q and -Q) that are separated by a distance equal to the side of the coin, the dipole moment of the dipole is:
The electrostatic potential energy of the electron in an orbit of hydrogen is \( -6.8 \) eV. The speed of the electron in this orbit is (C is the speed of light in vacuum):
The current passing through a coil of 120 turns and inductance \( 40 \) mH is \( 30 \) mA. The magnetic flux linked with the coil is:
A thin uniform rod of length L and certain mass is kept on a frictionless horizontal table with a massless string of length L fixed to one end (top view is shown in the figure). The other end of the string is pivoted to a point O. If a horizontal impulse P is imparted to the rod at a distance x = L/n from the mid-point of the rod (see figure), then the rod and string revolve together around the point O, with the rod remaining aligned with the string. In such a case, the value of n is _____.
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