List of top Physics Questions

A letter ' $A$ ' is constructed of a uniform wire with resistance $1.0\, \Omega$ per $cm$, The sides of the letter are $20\, cm$ and the cross piece in the middle is $10 \,cm$ long. The apex angle is $60$ . The resistance between the ends of the legs is close to:
An oscillator is nothing but an amplifer with
If the force is given by $ F = at + bt^2$ with $t$ as time. The dimensions of $a$ and $b$ are
The Young?s modulus of a perfectly rigid body is
The electric field intensity just sufficient to balance the earth's gravitational attraction on an electron will be: (given mass and charge of an electron respectively are $9.1 \times 10^{-31}\, kg$ and $\left.1.6 \times 10^{-19} C \right)$.
A large drop of oil (density $0.8 \,g / cm ^{3}$ and viscosity $\eta_{0}$ ) floats up through a column of another liquid (density $1.2\, g / cm ^{3}$ and viscosity $\eta_{L}$ ). Assuming that the two liquids do not mix, the velocity with which the oil drop rises will depend on :
If the unit of force and length be each increased by four times, then the unit of energy is increased by
A solid body of constant heat capacity $1 \,J/?C$ is being heated by keeping it in contact with reservoirs in two ways : (i) Sequentially keeping in contact with $2$ reservoirs such that each reservoir supplies same amount of heat. (ii) Sequentially keeping in contact with $8$ reservoirs such that each reservoir supplies same amount of heat. In both the cases body is brought from initial temperature $100^{\circ}C$ to final temperature $200^{\circ}C$. Entropy change of the body in the two cases respectively is :
A man of mass \(100 \,kg\). is standing on a platform of mass \(200 \,kg\). Which is kept on a smooth ice surface. If the man starts moving on the platform with a speed \(30 \,m/sec\) relative to the platform then calculate with what velocity relative to the ice the platform will recoil?
Which of the following must be known in order to determine the power output of an automobile?
Three resistors $1\,\Omega , 2\,\Omega$ and $3\,\Omega $ are connected to form a triangle. Across $3\,\Omega$ resistor a $3\,V$ battery is connected. The current through $3\,\Omega$ resistor is
In a common emitter amplifier the input signal is applied across
Charge passing through a conductor of cross-section area $A=0.3 \,m ^{2}$ is given by $q=3 t^{2}+5 t+2$ in coulomb, where $t$ is in second. What is the value of drift velocity at $t=2 s ?$ (Given, $\left.n=2 \times 10^{25} / \,m ^{3}\right)$
$A$ and $B$ are two metals with threshold frequencies $1.8 \times 10^{14}\, Hz$ and $2.2 \times 10^{4}\, Hz$ Two identical photons of energy $0.825 \,eV$ each are incident on them. Then photoelectrons are emitted by (Take $\left.h=6.6 \times 10^{-34} \,J - s \right)$
Two capacitors of capacities $1 \, \mu F$ and $C \, \mu F$ are connected in series and the combination is charged to a potential difference of $120 \,V$. If the charge on the combination is $80 \, \mu C$, the energy stored in the capacitor of capacity $C$ in $\mu J$ is
In the Wheatstone's network given, \(P = 10\,\Omega , Q = 20\,\Omega , R = 15 \,\Omega , S = 30 \,\Omega\), the current passing through the battery (of negligible internal resistance) is
Wheatstone's network
The potential of a large liquid drop when eight liquid drops are combined is 20 V. Then the potential of each single drop was
In hydrogen a atom, an electron is revolving in the orbit of radius $0.53\,�$ with $6.6 \times 10^{15}$ radiations/s. Magnetic field produced at the centre of the orbit is
In photoelectric emission process from a metal of work function $1.8 \,eV,$ the kinetic energy of most energetic electrons is $0.5 \,eV$. The corresponding stopping potential is
In the figure shown, the magnetic field induction as the point $O$ will be
A direct $X$ -ray photograph of the intenstines is not generally taken by radiologists because
The kinetic energy of an electron get tripled then the de-Broglie wavelength associated with it changes by a factor
A parallel plate capacitor has capacitance $C$. If it is equally filled the parallel layers of materials of dielectric constant $K_1$ and $K_2$ its capacity becomes $C_1$. The ratio of $C_1 $ and $C$ is
In the given circuit, the AC source has ? = 100 rad/s. Considering the inductor and capacitor to be ideal, the correct choice(s) is(are)
A uniform thin bar of mass $6m$ and length $12L$ is bent to make a regular hexagon. Its moment of inertia about an axis passing through the centre of mass and perpendicular to the plane of hexagon is