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Figure shows a potentiometer with length of wire $1\text{m}$ and resistance $10\Omega$. In this system, find length $l$ when galvanometer shows null deflection.

Find the current flowing through the resistance $R_1$ of the circuit shown in figure, if the resistances are equal to $R_1=10\Omega$, $R_2=10\Omega$ and $R_3=10\Omega$, and the potential of points $1,2$ and $3$ are equal to $V_1=10\text{V}$, $V_2=6\text{V}$ and $V_3=5\text{V}$.

What is the use of a lactometre?

A resistance of $20\Omega$ is connected to a source of alternating current rated $110\text{V},50\text{Hz}$. Find the time taken by the current to change from its first maximum value to the consecutive rms value.

A neutral conducting sphere of radius $R$ contains two spherical cavities of radii $a$ and $b$ that contains point charges $q_a$ and $q_b$ placed at the center of each cavity as shown in the figure below . Match the following table:

A particle starts from rest, accelerates at $2m/s^2$ for $10s$ and then goes with constant speed for $30s$ and then decelerates at $4m/s^2$ till it stops. What is the distance travelled by it?

When can we say that potential energy of an atom decrese or increase?when the separation increase and decrease.

The magnetic field in a region of space varies according to the equation$\overrightarrow{B}=B_0[x\hat{i}+y\hat{j}+\hat{k}]$. The magnetic flux associated with the area bounded by the line $x=0,y=0,x=a$ and $y=\frac{b}{2}$ in the $x-y$ plane is

A dip circle is so set that the dip needle moves freely in the magnetic meridian. In this position the angle of dip is ${39}^{\circ }$. Now the dip circle is rotated so that the plane in which the needle moves, makes an angle of ${30}^{\circ }$ with the magnetic meridian. In this position, the needle will dip by an angle :

n-p-n transistor has three leads A, B and C.
Connecting B and C by moist fingers, A to the
positive lead of an ammeter, and C to the
negative lead of the ammeter, one finds large
deflection. Then, A, B and C refer respectively
to :
(1) Emitter, base and collector
(2) Base, emitter and collector
(3) Base, collector and emitter
(4) Collector, emitter and base.

If the heat 110 J is added to a gaseous system and it acquires internal energy of 40 J, then the amount of internal work done is

Column - I gives electric and magnetic fields in different regions of space. Column - II gives possible path a charged particle in these regions. Match appropriately:

$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \left(A\right)\overrightarrow{E}=0,\overrightarrow{B}=B_0\hat{k}& \text{(p) Straight line}\\ \left(B\right)\overrightarrow{E}=E_0\hat{k},\overrightarrow{B}=0& \text{(q) Circle}\\ \left(C\right)\overrightarrow{E}=E_0\hat{k},\overrightarrow{B}=-B_0\hat{k}& \text{(r) Parabola}\\ \left(D\right)\overrightarrow{E}=-E_0\hat{k},\overrightarrow{B}=-B_0\hat{k}& \text{(s) Helix of increasing pitch}\\ & \text{(t) Helix of decreasing pitch}\end{array}$

A neutral particle at rest in a magnetic field decays into two charged particles of different masses but have equal amount of charges. The energy released goes into their kinetic energies. Then, what can be the path(s) of the two particles.



Neglect any interaction between the two charges.

A solid conducting sphere of radius $a$ has a net positive charge $2Q$. A conducting spherical shell of inner radius $b$ and outer radius $c$ is concentric with the solid sphere as shown in the figure and has a net charge $-Q$. The surface charge density on the inner and outer surfaces of the spherical shell will be

Figure shows electric field lines in which electric dipole p is placed as shown. Choose the correct statement

The dipole will experience a force towards:-

Consider the situation of the previous problem.Suppose each of the blocks is pulled by a constant force F instead of any impulse.Find the maximum elongation that the spring will suffer and the distances moved by the two blocks in the process.

In Young's double-slit experiment, using monochromatic light of wavelength $\lambda$, the fringe pattern shifts by a certain distance on the screen when a mica sheet of refractive index $1.6$ and thickness $2.0\mu \text{m}$ is introduced in the path of one of the interfering waves. The mica sheet is then removed and the distance between the plane of slits and the screen is doubled. It is found that the distance between successive maxima (or minima) now is the same as the observed fringe shift upon the introduction of the mica sheet. Calculate the wavelength of the light.

If the potentiometer gives a reading of 0, does that mean there is no potential drop across the circuit?

A bar magnet is demagnetised by inserting it inside a solenoid of length $0.2\text{m}$ , having $100$ turns and carrying a current of $5\text{A}$. The coercivity of the bar magnet is

In the figure, the final value of current in $10\Omega$ resistor, when switch $S$ is closed, is -

In Young's double slit experiment the separation $d$ between the slits is $2mm$. The wavelength $\lambda$ of the light used is $5896\AA$ and distance $D$ between the screen and slits is $100cm$. It is found that the angular width of the fringes is $0.20°$. To increase the fringe angular width to $0.21°$ (with same $\lambda$ and $D$) the separation between the slits needs to be changed to

A condenser $\text{A}$ has a capacity of $15\mu \text{F}$ when it is filled with a medium of dielectric constant $15$. Another condenser $\text{B}$ has a capacity of $1\mu \text{F}$ with air between the plates. Both are charged separately by a battery of $100\text{V}$. After charging, both are connected in parallel without the battery and the dielectric medium is removed. The common potential now is

1. 120

The energy required to remove electron from an atom in gaseous state is called?

A ball is thrown vertically downwards with speed $30\text{m/s}$ from the top of the tower of height $80\text{m}$. The speed of the ball with which it hits the grounds is $(g=10{\text{m/s}}^2)$

Which of the following graphs correctly represent a particle moving on a horizontal circle with angular acceleration of the particle directly proportional to $t$? Assume that the particle starts from rest.

A low pass filter has an input S/N of 20. The input voltage is 3 mV. Calculate the noise voltage.