List of top Physics Questions

Power dissipated across the $8 \,\Omega$ resistor in the circuit shown here is 2 watt. The power dissipated in watt units across the $3 \,\Omega$ resistor is :-
A cyclic process is shown in the figure. Work done during the cyclic process ABCDA is
A convex lens of focal length 20 cm made of glass of refractive index 1.5 is immersed in water having refractive index 1.33. The change in the focal length of lens is
The two slits are 1 mm apart from each other and illuminated with a light of wavelength $5 \times 10^{-7}$ m. If the distance of the screen is 1 m from the slits, then the distance between third dark fringe and fifth bright fringe is
A Carnot?s engine operates with source at $127?C$ and sink at $ 27?C$. If the source supplies 40 kJ of heat energy, the work done by the engine is
A block of wood floats in water with $\left( \frac{4}{5} \right)^{th}$of its volume submerged. If the same block just floats in a liquid, the density of the liquid (in Kg m$^{-3}$) is
Two capillary tubes of radii 0.2 cm and 0.4 cm are dipped in the same liquid. The ratio of heights through which liquid will rise in the tubes is
A wire suspended vertically from one of its ends is stretched by attaching a weight of 200 N to the lower end. The weight stretches the wire by 1 mm. Then the elastic energy stored in the wire is
Two bars $A$ and $B$ of circular cross-section and of same volume and made of the same material are subjected to tension. If the diameter of $A$ is half that of $B$ and if the force applied to both the rods is the same and it is in the elastic limit, the ratio of extension of $A$ to that of $B$ will be
From the top of a tower of height 40 m, a ball is projected upwards with a speed of ${20 \,m \, s^{-1}}$ at an angle of elevation of 30?. Then the ratio of the total time taken by the ball to hit the ground to its time to same height is Take ${g = 10 \, m \, s^{-2}}$
A boy walks to his school at a distance of 6 km with constant speed of ${2.5\, km \, h^{-1}}$ and walks back with a constant speed of ${4\, km \, h^{-1}}$. His average speed for round trip expressed in ${ km \, h^{-1}}$, is
A 280 day old radioactive substance shows an activity of 6000 dps, 140 days later its activity becomes 3000 dps. What was its initial activity?
X-rays, gamma rays and microwaves travelling in vacuum have
Two thin plano-convex lenses each of focal length $f$ are placed as shown in the figure. The ratio of their effective focal lengths in the three cases is
In the loop shown, the magnetic induction at the point $O$ is
A planet moving around sun sweeps area $A_1$ in $2$ days, $A_2$ in $3$ days and $A_3$ in $6$ days. Then the relation between $A_1, A_2 $ and $A_3$ is
When a mass is rotating in a plane about a fixed point, its angular momentum is directed along
If $v_e$ is escape velocity and $v _o$ is orbital velocity of a satellite for orbit close to the earth's suface, then these are related by
A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude $P_0$. The instantaneous velocity of this car is proportional to
An ammeter reads up to 1 A. Its internal resistance is 0.81 \( \Omega \). To increase the range to 10 A, the value of the required shunt is:
A 2 V battery, a 15 \( \Omega \) resistor, and a potentiometer of 100 cm length are connected in series. If the resistance of potentiometer wire is 5 \( \Omega \), then the potential gradient of the potentiometer wire is:
A coil of resistance 100 \( \Omega \) and inductance 5 H is connected to a 100 V battery. Then the energy stored in the coil is:
In Young's double slit experiment, the intensity of light at a point on the screen where the path difference is \( \lambda \) is:
The output voltage of a transformer connected to a 220 V line is 1100 V at 2 A current. Its efficiency is 100%. The current coming from the line is:
A nucleus \( _{Z}^A X \) emits an \( \alpha \)-particle. The resultant nucleus emits a \( \beta^- \)-particle. The respective atomic and mass numbers of final nucleus will be: