List of top Physics Questions

A long conducting wire having a current I flowing through it, is bent into a circular coil of $N$ turns .Then it is bent into a circular coil of $n$ turns. The magnetic field is calculated at the centre of coils in both the cases. The ratio of the magnetic field in first case to that of second case is :

The number of turns of the coil of a moving coil galvanometer is increased in order to increase current sensitivity by $50 \%$ The percentage change in voltage sensitivity of the galvanometer will be:

A body of mass $10 kg$ is moving with an initial speed of $20 m / s$ The body stops after $5 s$ due to friction between body and the floor The value of the coefficient of friction is: (Take acceleration due to gravity $g =10 ms ^{-2}$ )

Match List I with List II

List I		List II
A.	Microwaves	I.	Physiotherapy
B.	UV rays	II.	Treatment of cancer
C.	Infra-red rays	III.	Lasik eye surgery
D.	X-rays	IV.	Aircraft navigation

Choose the correct answer from the options given below:

Given below are two statements :
Statement I : In a typical transistor, all three regions emitter, base and collector have same doping level.
Statement II : In a transistor, collector is the thickest and base is the thinnest segment.
In the light of the above statements, choose the most appropriate answer from the options given below.

Heat energy of 735J is given to a diatomic gas allowing the gas to expand at constant pressure Each gas molecule rotates around an internal axis but do not oscillate The increase in the intemal energy of the gas will be :

A stone of mass $1 \, kg$ is tied to end of a massless string of length $1 m$ If the breaking tension of the string is $400\, N$, then maximum linear velocity, the stone can have without breaking the string, while rotating in horizontal plane, is :

A microscope is focused on an object at the bottom of a bucket If liquid with refractive index $\frac{5}{3}$ is poured inside the bucket, then microscope have to be raised by $30\, cm$ to focus the object again The height of the liquid in the bucket is :

A sinusoidal carrier voltage is amplitude modulated The resultant amplitude modulated wave has maximum and minimum amplitude of $120 \, V$ and $80\, V$ respectively The amplitude of each sideband is:

The charge flowing in a conductor changes with time as $Q(t)=\alpha t-\beta t ^2+\gamma^3$ Where $\alpha, \beta$ and $\gamma$ are constants Minimum value of current is :

Choose the correct relationship between Poisson ratio $(\sigma)$, bulk modulus $( K )$ and modulus of rigidity $(\eta)$ of a given solid object :

In a series $LR$ circuit with $X _{ L }= R$, power factor is $P _1$ If a capacitor of capacitance $C$ with $X _{ C }= X _{ L }$ is added to the circuit the power factor becomes $P_2$ The ratio of $P_1$ to $P_2$ will be :

A person has been using spectacles of power $-1.0$ dioptre for distant vision and a separate reading glass of power $2.0$ dioptres What is the least distance of distinct vision for this person :

The height of liquid column raised in a capillary tube of certain radius when dipped in liquid A vertically is, $5 cm$ If the tube is dipped in a similar manner in another liquid $B$ of surface tension and density double the values of liquid $A$, the height of liquid column raised in liquid $B$ would be ______$m$

Heat is given to an ideal gas in an isothermal process
A Internal energy of the gas will decrease
B Internal energy of the gas will increase
C Internal energy of the gas will not change
D The gas will do positive work E The gas will do negative work
Choose the correct answer from the options given below:

The magnetic moments associated with two closely wound circular coils $A$ and $B$ of radius $r _{ A }=10$ $cm$ and $r _B=20 cm$ respectively are equal if : (Where $N _A, I _A$ and $N _B, I _{ B }$ are number of turn and current of $A$ and $B$ respectively)

A massless square loop, of wire of resistance $10\, \Omega$, supporting a mass of $1 \, g$, hangs vertically with one of its sides in a uniform magnetic field of $10^3 G$, directed outwards in the shaded region A de voltage $V$ is applied to the loop For what value of $V$, the magnetic force will exactly balance the weight of the supporting mass of $1 g$ ?(If sides of the loop $=10 \, cm , g =10\, ms ^{-2}$ )

A massless square loop, of wire of resistance 10 Ω, supporting a mass of 1 g, hangs vertically with one of its sides in a uniform magnetic field

The pressure $( P )$ and temperature $( T )$ relationship of an ideal gas obeys the equation $PT ^2=$ constant The volume expansion coefficient of the gas will be :

Electric field in a certain region is given by $\overrightarrow{ E }=\left(\frac{ A }{x^2} \hat{i}+\frac{ B }{y^3} \hat{j}\right)$ The $SI$ unit of $A$ and $B$ are :

If the gravitational field in the space is given as $\left(-\frac{K}{r^2}\right)$ Taking the reference point to be at $r =2\, cm$ with gravitational potential $V =10 \,J / kg$ Find the gravitational potential at $r =3\, cm$ in SI unit (Given, that $K =6 \,Jcm / kg$)

Match List I with List II:

List - I		List - II
A.	Torque	I.	kg m^-1 s^-2
B.	Energy Density	II.	kg ms^-1
C.	Pressure gradient	III.	kg m^-2 s^-2
D.	Impulse	IV.	kg m² s^-2

Choose the correct answer from the options given below :

As shown in the figure, a point charge $Q$ is placed at the centre of conducting spherical shell of inner radius $a$ and outer radius $b$. The electric field due to charge $Q$ in three different regions I, II and III is given by: (I: r $<$ a, II: $a $<$ r $<$ b$, III: $r$>$b)$

An object is allowed to fall from a height $R$ above the earth, where $R$ is the radius of earth Its velocity when it strikes the earth's surface, ignoring air resistance, will be

For a simple harmonic motion in a mass spring system shown, the surface is frictionless When the mass of the block is $1\, kg$, the angular frequency is $\omega_1$ When the mass block is $2 \,kg$ the angular frequency is $\omega_2$ The ratio $\omega_2 / \omega_1$ is

A force is applied to a steel wire ' $A$ ', rigidly clamped at one end As a result elongation in the wire is $02\, mm$ If same force is applied to another steel wire ' $B$ ' of double the length and a diameter $24$ times that of the wire ' $A$ ', the elongation in the wire ' $B$ ' will be (wires having uniform circular cross sections)