List of top Physics Questions

Two identical wires A and B have the same length $L$ and carry the same current $I$. Wire A is bent into a circle of radius $R$ and wire B is bent to form a square of side $a$. If $B_1$ and $B_2$ are the values of magnetic induction at the centre of the square respectively, then the ratio $\frac{B_1{B_2}$ is}
An open organ pipe has a fundamental frequency of 300 Hz. The first overtone of a closed organ pipe has the same frequency as the first overtone of organ pipe. How long is each pipe?
Resistors $R_1$ and $R_2$ are placed in parallel as shown. If they have values of $5 \, \Omega$ and $10 \, \Omega$ respectively, their combined equivalent resistance is:
Resistors R1 and R2 are placed in parallel
In given circuit, all resistances are of $10 \Omega$. Current flowing through ammeter is
Which statement is correct for the given circuit?
A (+)vely charged particle is placed near an infinitely long straight conductor where there is zero gravity. Then
Two solenoids are given - 1st has 1 turn per unit length and 2nd has n turns per unit length. Ratio of magnetic fields at their centres is
Two point dipoles $p \hat{k}$ and $\frac{p}{2} \hat{k}$ are located at $(0,0,0)$ and $(1\, m , 0,2\, m )$ respectively. The resultant electric field due to the two dipoles at the point $(1 \,m , 0,0)$ is
A layer of oil with density $724\, kg/m^3$ floats on water of density $1000\, kg/m^3$. A block floats at the oil-water interface with $1/6$ of its volume in oil and $5/6$ of its volume in water, as shown in the figure. What is the density of the block?
The current in an $L-R$ circuit builds up to $\left(3 / 4^{\text {th }}\right)$ of its steady state value in $4$ seconds. The time constant of this circuit is
A square current carrying loop is changed to a circular loop in time $t_1$. Then
For a current carrying inductor, emf associated is 20mV. Now, current through it changes from 6A to 2A in 2s. The coefficient of mutual inductance is
Hologram is based on phenomenon of
The wavelength of an electron for transition from a state $n_1$ to $n_2$ is $\frac{ 9}{8R}$. Which of the following wavelengths is possible for a transition from $n_2$ to $n_1$.
In shown fig, the circular loop of wire is moved with velocity towards the infinite current carrying wire. Then
If $i_1 = 3 \, \sin \, \omega t$ and $i_2 = 4 \, \cos \, \omega t$, then $i_3$ is
A pendulum clock loses $12\,s$ a day if the temperature is $40^{\circ}C$ and gains $4\,s$ a day if the temperature is $20^{\circ}C$. The temperature at which the clock will show correct time, and the co-efficient of linear expansion $(\alpha)$ of the metal of the pendulum shaft are respectively :
The region between two concentric spheres of radii $'a'$ and $'b'$, respectively (see figure), has volume charge density $\rho = \frac{A}{r}$, where $A$ is a constant and $r$ is the distance from the centre. At the centre of the spheres is a point charge $Q$. The value of $A$ such that the electric field in the region between the spheres will be constant, is :
A satellite is revolving in a circular orbit at a height ' $h$' from the earth's surface (radius of earth $R ; h < < R$). The minimum increase in its orbital velocity required, so that the satellite could escape from the earth?s gravitational field, is close to : (Neglect the effect of atmosphere.)
A rigid ball of mass $m$ strikes a rigid wall at $60^�$ and gets reflected without loss of speed as shown in the figure. The value of impulse imparted by the wall on the ball will be
A ball is thrown from a point $A$ with a speed $u$ at an angle $\theta$ with the horizontal. If $g$ is the acceleration due to gravity, the total time taken for it to reach a point $B$ on the same horizontal plane is
Plancks constant $(h)$, speed of light in vacuum $(c)$ and Newton?s gravitational constant $(G)$ are three fundamental constants. Which of the following combinations of these has the dimension of length?
Potential difference between $A$ and $B$ in the following circuit
$'n'$ moles of an ideal gas undergoes a process $A \to B $ as shown in the figure. The maximum temperature of the gas during the process will be :
The magnitude of the sum of the two vectors is equal to the difference of their magnitudes, the angle between the vectors is,