List of top Physics Questions

A Carnot engine is working between $127^{\circ}C$ and $27^{\circ}C$. Keeping the sink temperature unaltered, the temperature at which the source has to be kept so as to double its efficiency is ________.
Water flows at $3~ms^{-1}$ in a horizontal pipe under a pressure of $2\times10^{5}~Nm^{-2}$. The pipe narrows to half its original diameter at one end. The speed of water (in $ms^{-1}$) in this narrow section is ________.
The angle of contact is the angle between ________.
In a liquid medium, if the depth increases, the pressure at that place ________.
The gravitational potential energy of a body of mass m on the surface of earth of mass M and radius R is ________.
The ratio of the escape velocity to the orbital velocity of the earth is ________.
The centre of mass of a thin uniform rod of length L lies at a distance (from one end) of ________.
A boy whirls a ball on a string along a horizontal circle of radius 98 cm. The angular velocity (in rad $s^{-1}$) so that its centripetal acceleration has the same magnitude as $g$ is ________.
If a spinning object contracts, its angular velocity ________.
A spring is stretched twice its initial extension. Compared to its initial value, the potential energy ________.
A car moves at a speed of $20~ms^{-1}$ under a force of 500 N. The power output of the car is ________.
A traffic light of mass $10\sqrt{3}$ kg is suspended by two cables making $30^{\circ}$ with the vertical. The tension in each cable is ________.
A tennis ball of mass 150 g is moving at $20~ms^{-1}$. A racket strikes it, reversing its direction with a final speed of $30~ms^{-1}$. If the contact time is 0.02 s, then the magnitude of the force (in N) exerted by the racket is ________.
The coefficient of friction is defined as the ratio of ________.
For the provided $v-t$ graph (decreasing line from $v_0$ to $0$), the correct statement is ________.
A car starts from rest with acceleration $a=6t (ms^{-2})$. Its velocity and displacement after 4 seconds are ________.
The SI unit of surface tension is ________.
The dimensions of $\frac{mB}{kT}$ where $m$ is magnetic moment, $B$ is magnetic flux density, $k$ is Boltzmann constant and $T$ is temperature are ________.
A photon has an energy of \( 3.2 \times 10^{-19} \, \text{J} \). What is the frequency of the photon?
A concave mirror produces an image of an object such that the distance between the object and image is 20 cm. If the magnification of the image is \( -3 \), then the magnitude of the radius of curvature of the mirror is:
State Kirchhoff’s laws. Apply these laws to find the values of current flowing in the three branches of the given circuit.
Kirchhoff’s laws.
A laser beam of frequency \( 3.0 \times 10^{14} \) Hz produces average power of 9 mW. Find (i) the energy of a photon of the beam, and (ii) the number of photons emitted per second on an average by the source.
When one end of the capillary is dipped in water, the height of water column is 'h'. The upward force of 108 dyne due to surface tension is balanced by the force due to the weight of water column. The inner circumference of the capillary is (surface tension of water $=7.2\times10^{-2}N/m$)
Two point charges $ +Q $ and $ -4Q $ are placed 60 cm apart. Where should a third charge be placed so that it experiences zero net force?
Quantities p, q, r, s are measured with errors 3%, 2%, 3% and 1%. $A = \frac{pq^{2}{r^{3}s}$. The percentage error in A is}