List of top Physics Questions

If two soap bubbles of different radii are connected by a tube:

A body is moving along a rough horizontal surface with an initial velocity $6 \,m/s$. If the body comes to rest after travelling a distance $9 \,m$, then the coefficient of sliding friction will be:

A plano-convex lens of refractive index $1.5$ and radius of curvature $30 \,cm $ is silvered at the curved surface. Now, this lens has been used to form the image of an object. At what distance from this lens, an object be placed in order to have a real image of the size of the object?

At the height $80\, m$, an aeroplane is moved with $150\, m / s . A$ bomb is dropped from it, so as to hit a target. At what distance from the target should the bomb be dropped ? $\left(g=10\, m / s ^{2}\right)$

For an exothermic reaction, the value of:

For a Carnot engine, the source is at $500\, K$ and the sink at $300\, K$. What is efficiency of this engine?

According to Heisenberg's uncertainty principle, the product of uncertainties in position and velocities for an electron of mass $ 9.1\times {{10}^{-31}}\,kg $ is:

Escape velocity at surface of earth is $11.2\,km/s$. Escape velocity from a planet whose mass is the same as that of earth and radius $1/4$ that of earth, is :

A $100\, m$ long train is moving with a uniform velocity of $45\, km/h$. The time taken by the train to cross a bridge of length $1\, km$ is:

Velocity-time curve for a body, projected vertically upwards, is:

The frequency of vibration of string is given by $ v=\frac{P}{2l}{{\left[ \frac{F}{m} \right]}^{1/2}} $ Here $ p $ is number of segments in the string and $l$ is the length. The dimensional formula for $ m $ will be:

A ball of mass $150\,g$ moving with an acceleration $20 \,m/s^2$ is hit by a force, which acts on it for $0.1\, s$. The impulsive force is :

A cylinder of mass $10 \,kg$ is rolling on a rough plane with a velocity of $10 \,m/s$. If the coefficient of friction between the surface and cylinder is $0.5$, then before stopping it will cover a distance of (Take $g = 10\, m/s^2$):

What is the value of linear velocity, if angular velocity is $3 \hat i - 4 \hat j + \hat k$ and distance from the centre is $5 \hat i - 6 \hat j + 6 \hat k$ ?

Figure shows a body of mass m moving with a uniform speed $v$ along a circle of radius $r$. The change in velocity in going from $A$ to $B$ is:

What is the value of linear velocity, if angular velocity is $3 \hat i - 4 \hat j + \hat k$ and distance from the centre is $5 \hat i - 6 \hat j + 6 \hat k$ ?

The angular momentum of a system of particles is not conserved :

Figure shows a body of mass m moving with a uniform speed $v$ along a circle of radius $r$. The change in velocity in going from $A$ to $B$ is:

A square wire frame of size $L$ is dipped in a liquid. On taking out, a membrane is formed. If the surface tension of liquid is $T$, the force acting on the frame will be :

Angular width $ (\theta ) $ of central maximum of a diffraction pattern of a single slit does not depend upon:

The first overtone of a stretched wire of given length is $320 \,Hz$. The first harmonic is :

Two identical conducting rods are first connected independently to two vessels, one containing water at 100$^{\circ}$C and the other containing ice at 0$^{\circ}$C. In the second case, the rods are joined end to end and connected to the same vessels. Let q$_1$ and q$_2$ gram per second be the rate of melting of ice in the two cases respectively. The ratio $\frac{q_1}{q_2}$ is

A black body at $200\, K$ is found to exit maximum energy at a wavelength $14\, \mu\, m$ When its temperature is raised to $1000\, K$, then wavelength at which maximum energy emitted is

The half-life of radium is $1620\, yr$ and its atomic weight is $226\, kg$ per kilomol. The number of atoms that will decay from its $1\, g$ sample per second will be (Avogadro's number $N=6.023 \times 10^{23}$ atoms/ $mol$ )

The electric potential at the surface of an atomic nucleus $(Z=50)$ of radius $9.0 \times 10^{-13} cm$ is