List of top Physics Questions

When a soap bubble is charged ?
Figure shows three points A, B and C in a region of uniform electric field \(\overrightarrow{E}\). The line AB is perpendicular and BC is parallel to the field lines. Then which of the following holds good? (VA, VB and VC represent the electric potential at points A, B and C respectively)
Figure shows three points A, B and C in a region
The difference between equivalent capacitances of two identical capacitors connected in parallel to that in series is $6 \,\mu F$ . The value of capacitance of each capacitor is
A dipole of dipole moment 'P' and moment of inertia I is placed in a uniform electric field \(\overrightarrow{E}\). If it is displaced slightly from its stable equilibrium position, the period of oscillation of dipole is
An infinitely long thin straight wire has uniform charge density of $\frac {1}{4} \times 10^{-2} cm^{-1}.$ What is the magnitude of electric field at a distance $20\, cm$ from the axis of the wire ?
The electric field lines on the left have twice the separation on those on the right as shown in figure. If the magnitude of the field at $A$ is $40\,Vm^{-1}$, what is the force on $20\,\mu \,C$ charge kept at $B$?
A point charge 'q' is placed at the corner of a cube of side 'a' as shown in the figure. What is the electric flux through the face ABCD?
A point charge 'q' is placed at the corner of a cube
A train whistling at constant frequency 'n' is moving towards a station at a constant speed V. The train goes past a stationary observer on the station. The frequency 'n' of the sound as heard by the observer is plotted as a function of time 't'. Identify the correct curve
A tray of mass $12 \,kg$ is supported by two identical springs as shown in figure. When the tray is pressed down slightly and then released, it executes SHM with a time period of $1.5\,s$. The spring constant of each spring is
A certain amount of heat energy is supplied to a monoatomic ideal gas which expands at constant pressure. What fraction of the heat energy is converted into work ?
In an adiabatic expansion of an ideal gas the product of pressure and volume
A sphere, a cube and a thin circular plate all of same material and same mass initially heated to same high temperature are allowed to cool down under similar conditions. Then the
Iceberg floats in water with part of it submerged. What is the fraction of the volume of iceberg submerged if the density of ice is $\rho_i = 0.917 \,g\,cm^{-3}$ ?
A wheel starting from rest gains an angular velocity of $10$ rad/s after uniformly accelerated for $5$ sec. The total angle through which it has turned is
Young's modulus of a perfect rigid body is
The value of acceleration due to gravity at a height of $10\,km$ from the surface of earth is $x$. At what depth inside the earth is the value of the acceleration due to gravity has the same value $x$?
Lenz's law gives
A double concave lens of refractive index 1.5 with its two spherical surfaces of radii R1 = 30 cm and R2 = 45 cm is kept in air. Its focal length is
A convex lens has a focal length of 10 cm. If u is the object distance, then the image distance is given by
The angle between the paraxial rays and principal axis is
A bird is flying vertically downwards the surface of water of a lake with constant speed. For a fish inside the water exactly below the bird, the bird appears to be
To examine the internal organs of a human body through light, the doctors use
A rectangular tank of depth 4 m is full of water of refractive index \(\frac{4}{3}\). When viewed from the top, the bottom of the tank is seen at a depth of 
The total internal reflection in diamond makes it shine, because the critical angle of diamond is
Ghee is converted from liquid to solid state during winter season. This process is called