List of top Physics Questions

Three charges of equal magnitude $q$ is placed at the vertices of an equilateral triangle of side $l$. The force on a charge $Q$ placed at the centroid of the triangle is

Three capacitors of capacitances $3\,\mu F$,$9\,\mu F$ and $18\,\mu F$ are connected once in series and another time in parallels. The ratio of equivalent capacitances in the two cases $(C_s/C_p)$ will be

Three charge q, Q and 4q are placed in a straight line of length l at points distant 0, $\frac{1}{2}$ and l respectively from one end. In order to make the net froce on q zero, the charge Q must be equal to

Three charges each equal to $+2 \,C$ are placed at the corners of an equilateral triangle. If the force between any two charges be $F$, then the net force on either will be :

Though quantum theory of light can explain a number of phenomena observed with light, it is necessary to retain the wave-nature of light to explain the phenomena of:

There is some change in length when a 33000 N tensile force is applied on a steel rod of area of cross-section $10^{-3}m^2$. The change of temperature required to produce the same elongation of the steel rod when heated is $(Y=3\times 10^{-11} \,N/m^2 , \alpha = 1.1 \times 10^{-5} /^0C )$

There are two types of electric charges positive charges and negative charges. The property which differentiates the two types of charges is

There is a horizontal fdm of soap solutions, on it a thread is placed in form of a loop. The film is pierced inside the loop and the thread becomes a circular loop of radius R. If the surface thension of soap solution is T. Then tension in the thread will be

There are two holes one each along the opposite sides of a wide rectangular tank. The cross section of each hole is $0.01\,m^2$ and the vertical .distance between the holes is one meter. The tank is filled with water. The net force on the tank in New ton when water flows out of the holes is : (Density of water $1000kg/m^3)$

There are four forces acting at a point $P$ produced by strings as shown in figure, which is at rest. The forces $F_{1}$ and $F_{2}$ are

There are certain material developed in laboratories which have a negative refractive index. A ray incident from air (medium $1$) into such a medium (medium $2$) shall follow a path given by

There are $2$ bodies of masses $100\, kg$ and $1000\,kg$ separated by a distance $1\,m$. At what distance from smaller body, the intensity of gravitational field will be zero

The working principle in atom bomb is

The word physics itself is due to Greek word

The work done by a body against friction always results in

The weight of the body is maximum in

The width of the forbidden band is small in the case of

The wheels are made circular because

The waves used by artificial satellites for communication is

The wavelength of sodium light in glass if it is 589.3 nm in air is (The refractive index of glass is 1.5).

The wavelength of X-rays which gives a diffraction angle, 2 $\theta$, equal to $16.80^{\circ}$ for a first order diffraction for a crystal with interplanar distance 0.200 nm, is (given sin $8.4^{\circ}$ and 0.146)

The wave impedance of free space is

The volume of atom in comparison to the volume of nucleus is of the order of

The volume of an air bubble increases by x% as it rises from the bottom of a lake to its surface. If the height of the water barometer is H, the depth of the lake is

The volume of a metal sphere increases by $0.24\%$ when its temperature is raised by $40^{\circ}C$. The coefficient of linear expansion of the metal is