List of top Physics Questions

When the displacement is half the amplitude the ratio of potential energy to the total energy is:
When light of wavelength 300 nm falls on a photoelectric emitter, photoelectrons are liberated. For another emitter, however light of 600 nm wavelength is sufficient for creating photoemission. What is the ratio of the work functions of the two emitters:
Two point charges + 3 $ \mu C $ and + 8 $ \mu C $ repel each other with a force of 40 N. If a charge of - 5 $ \mu C $ is added to each of them, then the force between them will become:
The dominant mechanisms for motion of charge carriers in forward and reverse biased silicon $ \text{p-n} $ junctions are:
At constant volume, temperature is increased. Then:
For a hollow cylinder and a solid cylinder rolling without slipping on an inclined plane, then which of these reaches earlier
A (100 W, 200V) bulb is connected to a to V power supply. The power consumption would be:
12. If the binding energy per nucleon in $ L{{i}^{7}} $ and $ H{{e}^{4}} $ nuclei are respectively 5.60 MeV and 7.06 MeV, then energy of reaction $ L{{i}^{7}}+p\xrightarrow{{}}2\,{{\,}_{2}}H{{e}^{4}} $ is:
In a double slit experiment instead of taking slits of equal widths, one slit is made twice as wide as the other, then in the interference pattern
A glass slab of thickness 4 cm contains same number of waves as 5 cm thickness of water, when both are traversed by the same monochromatic light. If the refractive index of water is 4/3, what is the refractive index of glass:
A 10kg body hangs at rest from a rope wrapped around a cylinder of 0.2 m in diameter. The torque applied about the horizontal axis of the cylinder is:
A spring of force constant $k$ is cut into two pieces such that one piece is double the length of the other. Then the long piece will have a force constant of
Wavelength of light of frequency 100 Hz
Four particles of masses m, 2m, 3m and 4m are arranged at the corners of a parallelogram with each side equal to a and one of the angle between two adjacent sides as $ 60{}^\circ $ . The parallelogram lies in the $ x-y $ plane with mass m at the origin and 4m on the $ x- $ axis. The centre of mass of the arrangement will be located at
The escape velocity of a sphere of mass m is given by (G = Universal gravitational constant; M = Mass of the earth and R = Radius of the e earth)
If a unit vector is represented by $ 0.5 \widehat{ i} - 0 . 8 \widehat{j} + c \widehat{k}$ then the value of c is
A mirror forms a real image of unit magnification. Its nature is
A concave lens of glass, refractive index 1.5 has both surfaces of same radius of curvature R. On immersion in a medium of refractive index 1.75, it will behave as a
There are two liquid drops of different radii. The excess pressure inside over the outside is:
Yellow light is used in a single slit diffraction experiment with slit width of 0.6 mm. If yellow light is replaced by X-rays, then the observed pattern will reveal
A body is sliding on a smooth inclined plane requires 4 second to reach the bottom starting from rest at the top. How much rime does it take to cover $ \frac{1}{4} $ the distance starting from rest?
A photocell stops emission if it is maintained at 2 V positive potential. The energy of most energetic photoelectron is:
A bullet of mass 50 g is fired from a 5 kg gun with a velocity of 1 km/sec. The speed of recoil of the gun is:
Two spheres made of same substance have diameters in the ratio 1 : 2. Their thermal capacities are in the ratio of:
A straight wire of diameter 0.5 mm carrying a current of 1 A is replaced by the another wire of 1 mm diameter carrying the same current. The strength of the magnetic field far away is