List of top Physics Questions

In the circuit diagram ,heat produces in $R, 2R$ and $1.5 \,R$ are in the ratio

A rectangular coil of $100$ turns and size $0.1 \,m \times 0.05\, m$ is placed perpendicular to a magnetic field of $0.1 \,T$. If the field drops to $0.05 \,T$ in $0.05$ second, the magnitude of the e.m.f. induced in the coil is

In a lift moving up with an acceleration of $5\,ms^{-2}$ a ball is dropped from a height of $1.25\,m$ .The time taken by ball to reach the floor of the lift is........(nearly)$(g=10\, ms^{-2})$

A students plots a graph between inverse of magnification 1/$m$ produced by a convex thin lens and the object distance $u$ as shown in figure. What was the focal length of the lens used?

A network of resistances, cell and capacitor $C( = 2 \,\mu F)$ is shown in adjoining figure. In steady state condition, the charge on $2 \,\mu F $capacitor is $Q$, while $R$ is unknown resistance. Values of $Q$ and $R$ are respectively

The dimensional formula of magnetic flux is

The centre of a wheel rolling on a plane surface moves with a speed $v_{ 0}$. A particle on the rim of the wheel at the same level as the centre will be moving at speed

If the work done in turning a magnet of magnetic moment $M$ by an angle of 90$^{\circ}$ from the magnetic meridian is $n$ times the corresponding work done to turn it through an angle of 60$^{\circ}$, then the value of $n$ is

Mobilities of electrons and holes in a sample of intrinsic germanium at room temperature are $0.36\,m^2V^{-1}s^{-1}$ and $0.17\,m^2V^{-1}s^{-1}$. The electron and hole densities are each equal to $2.5 \times 10^{19} m^3$. The electrical conductivity of germanium is

$0.1\,m^{3}$ of water at $80\,^\circ$C is mixed with $0.3\,m^3$ of water at $60\,^\circ$C. The final temperature of the mixture is

In an unbiased $p-n$ junction, holes diffuse from the $p$-region to $n$-region because of

A wave travelling in the $+ve$ $x-direction$ having displacement along $y$-direction as $1m$, wavelength $2 \pi m$ and frequency of $ \frac{1}{\pi} Hz$ is represented by :

In the circuit $R_1 = R_2$.The value of $E$ and $R_1$ are ________($E-EMF,R_1$-resistance)

In $R-L-C$ series circuit, the potential differences across each element is $20\,V$. Now the value of the resistance alone is doubled, then $P.D.$ across $R, L$ and $C$ respectively

Pick out the correct statements from the following: (I) Electron emission during $\beta$-decay is always accompained by neutrino (II) Nuclear force is charge independent. (III) Fusion is the chief source of stellar energy

Find out the effective capacitance between points A and B as shown in the figure. Here ${C_1 = C_2 = 20 \, \mu F }$ and ${C_3 = C_4 = 10 \, \mu F}$

The velocity-time graph of particle comes out to be a non-linear curve. The motion is

The quantity which has the same dimensions as that of gravitational potential is

See the diagram. Area of each plate is $2.0\,m^2$ and $d = 2\times 10^{-3} C$ is given to $Q$.Then the potential of $Q$ becomes

Two solids $P$ and $Q$ float in water. It is observed that $P$ floats with half of its volume immersed and $Q$ floats with $\frac{2}{3^{rd}}$ of its volume is immersed. The ratio of densities of $P$ and $Q$ is

$A$ and $B$ are the two radioactive elements. The mixture of these elements show a total activity of $1200$ disintegrations/minute. The half life of $A$ is $1$ day and that of $B$ is $2$ days.What will be the total activity after $4$ days ? Given : The initial number of atoms in $A$ and $B$ are equal.

A particle is moving with a uniform speed $v$ in a circular path of radius $r$ with the centre at $O$. When the particle moves from a point $P$ to $Q$ on the circle such that $? POQ=\theta$, then the magnitude of the change in velocity is

A mass $M$ at rest is broken into two pieces having masses $m$ and $(M-m)$. The two masses are then separated by a distance $r$. The gravitational force between them will be the maximum when he ratio of the masses $[m:(M-m)]$ of the two parts is

A biconvex lens of focal length $f$ and radii of curvature of both the surfaces $R$ is made of a material of refractive index $n_1$. This lens is placed in a liquid of refractive index $n_2$. Now this lens will behave like

A circular loop of radius 0.3 cm lies parallel to a much bigger circular loop of radius 20 cm. The centre of the smaller loop is on the axis of the bigger loop. The distance between their centres is 15 cm. If a current of 2.0 A flows through the bigger loop, then the flux linked with smaller loop is