List of top Physics Questions

A equiconvex lens is cut into two halves along (i) XOX and (ii)YOY as shown in the figure. Let f,ff be the focal lengths of the complete lens,of each half in case (i), and of each half in case (ii), respectively 

Choose the correct statement from the following

A charged particle moves through a magnetic field in a direction perpendicular to it. Then the
A charge q is located at the centre of a cube. The electric flux through any face is:

Two 220-volt, 100-watt bulbs are connected first in series and then in parallel. Each time the combination is connected to a 220-volt a.c. supply line. The power drawn by the combination in each case respectively will be:

In a Wheatstone's bridge all the four arms have equal resistance R. If the resistance of the galvanometer arm is also R,the equivalent resistance of the combination as seen by the battery is:

A man weighs 80 kg, he stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of 5 m/s2. What would be the reading on the scale? (g=10 m/s2) 
A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m then-
A charged particle is suspended in equilibrium in a uniform vertical electric field of intensity $ 20000\,\,V/m $ . If mass of the particle is $ 9.6\times {{10}^{-16}}kg $ , the charge on it and excess number of electrons on the particle are respectively $ (g=10\,m/s^2) $ :

The radius of electron's second stationary orbit in Bohr's atom is R. The radius of 3rd orbit will be

The size of the image of an object, which is at infinity, as formed by a convex lens of focal length 30 cm is 2 cm. If a concave lens of focal length 20 cm is placed between the convex lens and the image at a distance of 26 cm from the convex lens, calculate the new size of the image.
The half-life of a radioactive substance is $3.6$ days. How much of $ 20\,\,mg $ of this radioactive substance will remain after $36$ days:
A man throws balls with the same speed vertically upwards one after the other at an interval of $2s$. What should be the speed of the throw so that more than two balls are in the sly at any time? (Given $g = 9.8\, m/s^2$)
The time period of a particle in simple harmonic motion is 8 second. At t = 0 it is at the mean position. The ratio of the distances travelled by it in the first and second seconds is:
The frequency of a light ray is $ 6\times {{10}^{4}}\,\,Hz $ . Its frequency when it propagates in a medium of refractive index $1.5$, will be:
Between the plates of parallel plate capacitor of capacity C, two parallel plates of the same material and area same as the plate of the original capacitor, are placed. If the thickness of these plates is equal to 1/5th of the distance between the plates of the origin

A bird of mass 1.23 kg is able to hover by imparting a downward velocity of \(10 ms^{-1}\) uniformly to air of density \(\rho kg-m^{-3}\) over an effective area \(0.1 m^2\). If the acceleration due to gravity is \(10 ms^{-2}\) then the magnitude of \(\rho\) is in \(kg-m^{-3}\)

The kinetic energy of 4 moles of nitrogen gas at $ \text{127}{{\,}^{\text{o}}}\text{C} $ is ...... cals. $ \text{(R= 2 cal mo}{{\text{l}}^{-1}}{{\text{K}}^{-1}}\text{)} $
The atomic number and mass number (M) of the nucleide formed when three alpha $ (\alpha ) $ and two beta $ (\beta ) $ particles are emitted from $ {{\,}_{\text{92}}}{{\text{U}}^{\text{238}}}\text{.} $
A monkey of mass $20\, kg$ is holding a vertical rope. The rope will not break when a mass of $25\, kg$ is suspended from it but will break if the mass exceeds $25\, kg.$ What is the maximum acceleration with which the monkey can climb up along the rope ? $(g = 10\, m/s^2)$
Consider a compound slab consisting of two different materials having equal thicknesses and thermal conductivities $K$ and $2\, K,$ respectively. The equivalent thermal conductivity of the slab is
The molar heat capacity of water at constant pressure, $C$, is $75\, JK ^{-1}\, mol ^{-1}$. When $1.0\, KJ$ of heat is supplied to $100\, g$ of water which is free to expand, the increase in temperature of water is :
Solar energy is mainly caused due to
A nuclear reaction is given by,
 ZXA → Z+1YA +–1e0+\(\bar v\) represents 
A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will
The time period of mass suspended from a spring is $T$. If the spring is cut into four equal parts and the same mass is suspended from one of the parts, then the new time period will be