List of top Physics Questions

An element consists of a mixture of three isotopes A, B, and C of masses \( m_1 \), \( m_2 \), and \( m_3 \) respectively. If the relative abundances of the three isotopes A, B, and C is in the ratio 2:3:5, the average mass of the element is:
In a series LCR circuit, if the current leads the source voltage, then:
If the amplitude of the magnetic field part of a harmonic electromagnetic wave in vacuum is \( 270 \) nT, the amplitude of the electric field part of the wave is:
A rectangular coil of 400 turns and \(10^{-2} \, \text{m}^2\) area, carrying a current of 0.5 A is placed in a uniform magnetic field of 1 T such that the plane of the coil makes an angle of 60° with the direction of the magnetic field. The initial moment of force acting on the coil in Nm is:
The most exotic diamagnetic materials are:
Two circular coils of radii \(r_1\) and \(r_2\) (\(r_1 \ll r_2\)) are placed coaxially with their centers coinciding. The mutual inductance of the arrangement is:
The efficiency of a reversible heat engine working between two temperatures is 50\%. The coefficient of performance of a refrigerator working between the same two temperatures but in reverse direction is:
The total internal energy of 4 moles of a diatomic gas at a temperature of \(27^\circ C\) is: (Universal gas constant \( R = 8.31 \, \text{J mol}^{-1} \text{K}^{-1} \))
The temperature on a Fahrenheit temperature scale that is twice the temperature on a Celsius temperature scale is:
The energy required to take a body from the surface of the earth to a height equal to the radius of the earth is \( W \). The energy required to take this body from the surface of the earth to a height equal to twice the radius of the earth is:
The work done in increasing the diameter of a soap bubble from 2 cm to 4 cm is (Surface tension of soap solution \(=3.5\times10^{-2}Nm^{-1}\))
The height of water level in a tank of uniform cross-section is 5 m. The volume of the water leaked in 5 s through a hole of area \(2.4~mm^{2}\) made at the bottom of the tank is (Assume the level of the water in the tank remains constant and acceleration due to gravity \(=10~ms^{-2}\))
A steel wire of length 3 m and a copper wire of length 2.2 m are connected end to end. When the combination is stretched by a force, the net elongation is 1.05 mm. If the area of cross-section of each wire is 6 mm², then the load applied is: (Young’s moduli of steel and copper are respectively \(2 \times 10^{11} \, \text{Nm}^{-2}\) and \(1.1 \times 10^{11} \, \text{Nm}^{-2}\)).
A block of mass 0.5 kg is at rest on a horizontal table. The coefficient of kinetic friction between the table and the block is 0.2. If a horizontal force of 5 N is applied on the block, the kinetic energy of the block in a time of 4 s is (Acceleration due to gravity = 10 m/s\(^2\))
A car is moving on a circular track banked at an angle of 45°. If the maximum permissible speed of the car to avoid slipping is twice the optimum speed of the car to avoid the wear and tear of the tyres, then the coefficient of static friction between the wheels of the car and the road is
Regarding fundamental forces in nature, the correct statement is
A body is falling freely from the top of a tower of height 125 m. The distance covered by the body during the last second of its motion is \(x\%\) of the height of the tower. Then \(x\) is (Acceleration due to gravity = 10 m/s\(^2\))
During the formation of p - n junction:
A train with an axle of length 1.66 m is moving towards north with a speed of 90 km/h. If the vertical component of the earth’s magnetic field is \( 0.2 \times 10^{-4} \) T, the emf induced across the ends of the axle is:
The natural frequency of an LC circuit is 120 kHz. When the capacitor in the circuit is totally filled with a dielectric material, the natural frequency of the circuit decreases by 20 kHz. The dielectric constant of the material is:
A plane electromagnetic wave of electric and magnetic fields \( E_0 \) and \( B_0 \) respectively incidents on a surface. If the total energy transferred to the surface in a time of \( t \) is \( U \), then the magnitude of the total momentum delivered to the surface for complete absorption is:
The related effort to derive the properties of a bigger, more complex system from the properties and interactions of its constituent simpler parts is:
The error in the measurement of resistance, when \( (10 \pm 0.5) \) A current passing through it produces a potential difference of \( (100 \pm 6) \) V across it, is:

A big liquid drop splits into 'n' similar small drops under isothermal conditions, then in this process:

The process of the loss of strength of a signal while propagating through a medium is