List of top Physics Questions asked in WBJEE

Force required to move a mass of $1 \,kg$ at rest on a horizontal rough plane ( $ \mu =0.1 $ and $ g=9.8\,m{{s}^{2}} $ ) is

A shell of mass $10\, kg$ is moving with a velocity of $ 10\,ms^{-1}$ when it blasts and forms two parts of mass $9 \,kg$ and $1 \,kg$ respectively. If the $1^{st}$ mass is stationary, the velocity of the $ 2^{nd} $ is

A bullet emerge from a barrel of length $1.2\, m$ with a speed of $640\, ms ^{-1}$. Assuming constant acceleration, the approximate time that it spends in the barrel after the gun is fired is

When sound is produced in an aeroplane moving with a velocity of $200 \,m/s$ horizontal its echo is heard after $ 10\sqrt{5}\,s. $ If velocity of sound in air is the elevation of aircraft is

A battery of e. m. f. $E$ and internal resistance $r$ is connected to an external resistance $R$ the condition for maximum power transfer is

The binary number $10111$ is equivalent to the decimal number

Two stretched strings have lengths $l$ and $2l$ while tension are $T$ and $4T$ respectively. If they are made of same material the ratio of their frequency is

The displacement ($x$) of a particle depends on time ($t$) as $x = \alpha t^2 - \beta t^3$. Then, $\alpha \beta$ is:

Number of particles passing in unit time through unit area perpendicular to the z-axis is given by: 
$N = D \dfrac{(N_2 - N_1)}{(Z_2 - Z_1)}$, 
where $N_2$ and $N_1$ are the number of particles in unit volume at $Z_2$ and $Z_1$. The dimensional formula of $D$ is?

A proton is projected with a velocity 10⁷ ms^-1 at right angles to a uniform magnetic field of induction 100 mT. The time (in seconds) taken by the proton to traverse 90^o arc is(Mass of proton = 1.65 × 10^-27 kg and charge of proton = 1.6 × 10^-19 C)

A conducting sphere of radius R, carrying charge Q, lies inside an uncharged conducting shell of radius 2R. If they are joined by a metal wire, then

At a given place where acceleration due to gravity is ' $8^{\prime }\mathrm{m}/{\mathrm{s}}^2,$ a sphere of lead of density 'd' $\mathrm{kg}/{\mathrm{m}}^3$ is gently released in a column of liquid of density $\rho \mathrm{kg}/{\mathrm{m}}^3$. If $\mathrm{d}>\rho$, the sphere will

Two disks of equal mass but different diameter are connected with an axle system that allows them to roll down an inclined plane together. Both disks start and finish at the same time. Which of the following statements best describes the disks?

The value of F so as to keep the smooth wedge stationary, when it is loaded with a block of mass M, which is connected with a light inextensible string, will be

Two mirrors at an angle θº produce 5 images of a point. The number of images produced when θ is decreased to θº – 30º is

The equation of transverse wave is given by $y=5\sin 2\pi (\frac{t}{0.04}-\frac{x}{40}),$ where distance is in $\mathrm{cm}$ and time insecond. The wavelength of wave will be

A copper bar of length 1 m and cross-sectional area 10 × 10^-2 m² has its one end maintained at 100^oC by means of 0.4 kW electric heater. What is the temperature of the other end in steady state, given that the thermal conductivity of copper is 400 W/mK?

A small ball is connected to a block by a light string of length L. Both are initially on the ground. There is sufficient friction on the ground to prevent the block from slipping. The ball is projected vertically upwards with a velocity u, where 2gl < u² < 3gl. The centre of mass of the 'block + ball' system is C. Then,

The temperature of an ideal gas is increased from 120 K to 480 K. If at 120 K, the root mean square speed of gas molecules is v, then at 480 K it will be

The light beams of intensities in the ratio of 9 : 1 are allowed to interfere. What will be the ratio of the intensities of maxima and minima ?

The electric potential at a point on the axis of an electric dipole depends upon the distance r (> > a) of the point from centre of the dipole as

The potential energy of a particle varies with distance $x$ from a fixed origin as $\vee =\left(\frac{A\sqrt{x}}{x+B}\right),$ where $A$ and $B$ are constants. The dimensions of AB are

If the length of the second's hand in a stop-clock is 3 cm, then the angular velocity and linear velocity of the tip is

Experimental investigations show that the intensity of solar radiation is maximum for a wavelength 480 nm in the visible region.Estimate the surface temperature of sun. Given Wein’s constant b = 2.88 × 10^–3 mK.

A particle moves in xy plane according to the law x = a sin ωt and y = a(1 - cos ωt), where a and w are constant. The particle traces