List of top Physics Questions

Four metal plates are arranged as shown. Capacitance between $X$ and $Y (A \to$ Area of each plate, $d \to$ distance between the plates)
Effective resistance between $A$ and $B$ in the following circuit
A metallic wire of cross sectional area $ 4 \, mm^{2} $ carries a current of $ 3.2 \, A $ . If $ 5 \times 10^{26} $ charge carriers flow across the wire per unit volume, then their drift velocity in $ m \,s^{-1} $ is
An $1800\, W$ toaster, a $1.3 \, KW$ electric fan and a $100W$ lamp are plugged in the same $120V$ circuit i.e. all the three devices are in parallel. What is the approximate value of the total current (i.e. sum of the current drawn by the three devices) through circuit ?
The equation of continuity in incompressible fluid flow is based on the principle of conservation of
The flow of liquid in a tube is laminar, when the value of Reynold�s number lies between
In a room where the temperature is $30^{\circ}C$ a body cools from $61^{\circ}C$ to $59^{\circ}C$ in 4 minutes. The time taken by the body to cool from $51^{\circ}C$ to $49^{\circ}C$ will be about
A body falls freely for $10\,sec$. Its average velocity during this journey (take $g = 10 \, ms^{-2}$)
Alternating current of peak value $\left(\frac{2}{\pi}\right)$ ampere flows through the primary coil of the transformer. The coefficient of mutual inductance between primary and secondary coil is 1 henry. The peak e.m.f. induced in secondary coil is (Frequency of $AC = 50\, Hz$)
A pan filled with hot food cools from $94 ^{\circ}C$ to $86^{\circ}C$ in $2$ minutes. When the room temperature is $20 ^{\circ}C$. How long will it cool from $74 ^{\circ}C$ to $66 ^{\circ}C$ ?
Two identical parallel plate air capacitors are connected in series to a battery of e.m.f. $V$. If one of the capacitor is completely filled with dielectric material of constant $K$, then potential difference of the other capacitor will become
The magnetic field intensity at the centre of cubical cage of identical wires of length ?a? due to a current I flowing as shown in the fiigure is
To find the focal length of a convex mirror, a student records the following data : The focal length of the convex lens is $f_1$ and that of mirror is $f_2$. Then taking index correction to be negligibly small, $f_1$ and $f_2$ are close to :
The magnetic field at the centre O of the arc shown in the figure is
A rectangular loop has a sliding connector PQ of length $\ell$ and resistance $R\,\Omega$ and it is moving with a speed v as shown. The set-up is placed in a uniform magnetic field going into the plane of the paper. The three currents $I_1,\, I_2$ and $I$ are
The density of a newly discovered planet is twice that of earth. The acceleration due to gravity at the surface of the planet is equal to that at the surface of the earth. If the radius of the earth is $R$, the radius of the planet would be
A length-scale $(\ell)$ depends on the permittivity $(\varepsilon)$ of a dielectric material, Boltzmann constant $\left( k _{ B }\right)$, the absolute temperature $(T)$, the number per unit volume $(n)$ of certain charged particles, and the charge $(q)$ carried by each of the particles. Which of the following expressions (s) for $\ell$ is (are) dimensionally correct?
Three particles $ P, Q $ and $ R $ are at rest at the vertices of an equilateral triangle of side $ s $ . Each of the particles starts moving with constant speed $ v \,ms^{-1}. P $ is moving along $ PQ, Q $ along $ QR $ and $ R $ along $ RP $ . The particles will meet each other at time $ t $ given by
In the following network potential at $'O'$
Variation of resistance of the conductor with temperature is as shown .The temperature co-efficient $(\alpha)$ of the conductor is
A 220 volt - 1000 watt bulb is connected across a 110 volt mains supply. The power consumed will be
Three resistances $P, Q, R$ each of $2\, \Omega$ and an unknown resistance $S$ form the four arms of a Wheatstone bridge circuit. When a resistance of $6\, \Omega$ is connected in parallel to $S$ the bridge gets balanced. What is the value of $S$ ?
In a potentiometer, auniform potential gradient of $ 0.8 \,V \,m^{-1} $ is maintained across its $ 10 \,m $ wire. The potential difference across two points on the wire located at $ 0 \,m \,65\, cm $ and $ 2 \,m\, 45 \,cm $ is
Mobility of free electrons in a conductor is
A particle executing $SHM $ has a maximum speed of $0.5 \, ms^{ -1}$ and maximum acceleration of $1.0 \, ms^{-2}$ The angular frequency of oscillation is