List of top Physics Questions

On a new scale of temperature (which is linear) and called the W scale, the freezing and boiling points of water are 39$^{\circ}$W and 239$^{\circ}$W respectively. What will be the temperature on the new scale, corresponding to a temperature of 39$^{\circ}$C on the Celsius scale?
A thin conducting ring of radius R is given a charge + The electric field at the center O of the ring due to the charge on the part AKB of the ring is E. The electric field at the center due to the charge on the part ACDB of the ring is
A cell can be balanced against 110 cm and 100 cm of potentiometer wire, respectively with and without being short circuited through a resistance of $10\, \Omega.$ Its internal resistance is
A wire of a certain material is stretched slowly by ten percent. Its new resistance and specific resistance become respectively
Electrical force between two point charges is 200 N. If we increase 10% charge on one of the charges and decrease 10% charge on the other, then electrical force between them for the same distance becomes
Advantages of optical fibre communications over two wire transmission line or co-axial cable transmission are
There are $ 2.0 \times 10^{24} $ molecular dipoles in a paramagnetic salt. Each has dipole moment $ 1.5 \times 10^{23} Am^2 $. Find maximum (saturation) magnetization in the specimen.
If 20 J of work has to be done to move an electric charge of 4 C from a point, where potential is 10 V to another point, where potential is V volt, find the value of V.
A bar magnet of magnetic moment M, is placed in a magnetic field of induction B. The torque exerted on it is
A pure Ge specimen is doped with Al. The number density of acceptor atoms is approximately 10$^{21} m^{-3}$. If density of electron hole pair in an intrinsic semiconductor is approximately 10$^{19} m^{-3}$, the number density of electrons in the specimen is
First order derivation of thermo emf produced in thermo-couple with respect to temperature gives ........
The de-Broglie wavelength associated with a particle moving with momentum $(p)$ and mass $(m)$ is
The deflection in a moving coil galvanometer falls from 50 divisions to 10 divisions,when a shunt of $ 2? $ is connected with it. The resistance of galvanometer coil is
Two electric bulbs are connected one by one across potential difference V. At that time power consumed in them are $P_1 \, and \, P_2 $ respectively. Now, if potential difference V is applied across series combination of these bulbs, what will be total power consumed ?
The internal resistance of a cell of emf 4 V is $ 0.1 \Omega $ It is connected to a resistance of $ 3.9 \Omega $. The voltage across the cell will be
The ratio of cross-sectional areas of two conducting wires made up of same material and having same length is 1 : 2. What will be the ratio of heat produced per second in the wires, when same current is flowing in them?
Colours in thin films are due to
A rocket of mass $100 \,kg$ burns $0.1\, kg$ of fuel per sec. If velocity of exhaust gas is $1 \,km/s^{-1}$, then it lifts with an acceleration of
A beaker of radius $15\, cm$ is filled with a liquid of surface tension $0.75\, N/m$. Force across an imaginary diameter on the surface of the liquid is
Force required to move a mass of $1 \,kg$ at rest on a horizontal rough plane ( $ \mu =0.1 $ and $ g=9.8\,m{{s}^{2}} $ ) is
A shell of mass $10\, kg$ is moving with a velocity of $ 10\,ms^{-1}$ when it blasts and forms two parts of mass $9 \,kg$ and $1 \,kg$ respectively. If the $1^{st}$ mass is stationary, the velocity of the $ 2^{nd} $ is
Identify the INCORRECT statement regarding a superconducting wire
A certain radioactive material $_{Z} X ^{A}$ starts emitting $\alpha$ and $\beta$ particles successively such that the end product is $_{z-3} Y ^{A-8}$. The number of $\alpha$ and $\beta$ particles emitted are
A particle shows distance - time curve as given in this figure. The maximum instantaneous velocity of the particle is around the point
An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature $20^\circ C ?$ The temperature of boiling water is $100^\circ C $