List of top Physics Questions asked in JCECE

Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to the minimum intensity is 25. The intensities of the sources are in the ratio
The centre of mass of three particles of masses 1 kg, 2 kg and 3 kg is at (3, 3, 3) with reference to a fixed coordinate system. Where should a fourth particle of mass 4 kg be placed, so that the centre of mass of the system of all particles shifts to a point (1, 1, 1)?
The angular width of the central maximum of the diffraction pattern in a single slit of width a experiment, with $ \lambda $ as the wavelength of light, is
At what angle must the two forces (x + y) and (x - y) act so that the resultant may be $\sqrt{x^2 + y^2}$ ?
A radioactive material decays by simultaneous emission of two particles with half-lives 1620 yr and 810 yr respectively. The time in year after which one-fourth of the material remains, is
A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity. Then the pressure in the compartment is
A thin lens made of glass of refractive index $\mu = 1.5$ has a focal length equal to 12 cm in air. lt is now immersed in water $\bigg(\mu = \frac{4}{3}\bigg).$ Its new focal length is
Air is pumped into an automobile tube upto a pressure of 200 kPa in the morning when the air temperature is 22$^{\circ}$C. During the day, temperature rises to 42$^{\circ}$C and the tube expands by 2 %. The pressure of the air in the tube at this temperature, will be approximately
A ray PQ incident on the refracting face BA is refracted in the prism BA C as shown in the figure and emerges from the other refracting face AC as RS, such that AQ = AR. If the angle of prism $A = 60^\circ$ and the refractive index of the material of prism is $\sqrt 3,$ then the angle of deviation of the ray is
Two capillary of lengths L and 2L and of radii R and 2R are connected in series. The net rate of flow of fluid through them will be (Given rate of the flow through single capillary.$X=\frac{\pi pR^4}{8\eta L})$
A 16 kg block moving on a frictionless horizontal surface with a velocity of 4 m/s compresses an ideal spring and comes to rest. If the force constant of the spring be 100 N/m, then the spring is compressed by
Ideal gas and real gas have major difference of
A parallel plate air capacitor has a capacitance $C$. When it is half filled with a dielectric of dielectric constant $5$, the percentage increase in the capacitance will be :
A free neutron decays spontaneously into
A sealed container with negligible coefficient of volumetric expansion contains helium (a monoatomic gas). When it is heated from 300 K to 600 K, the average KE of helium atoms is
A choke is preferred to a resistance for limiting current in AC circuit because
The equation of a simple harmonic wave is given by $y=5\, \sin \frac{\pi}{2}(100\, t-x)$, where $x$ and $y$ are in meter and time is in second. The period of the wave in second will be
The twinkling effect of star light is due to
A beam of monochromatic blue light of wavelength $4200\, ?? in air travels in water of refractive index $4/3$. Its wavelength in water will be:
A ball is thrown from a point with a speed $ {{\text{v}}_{\text{0}}} $ at an angle of projection $ \theta . $ From the same point and at the same instant, a person starts running with a constant speed $ \frac{{{v}_{0}}}{2} $ to catch the ball. Will the person be able to catch the ball? If yes, what should be the angle of projection?
The mass of the earth is $6 \times 10^{24}\, kg$ and that of the moon is $7.4 \times 10^{22}\, kg$. The potential energy of the system is $-7.79 \times 10^{28}\, J$. The mean distance between the earth and moon is $(G = 6.67 \times 10^{-11}\, N\, m^2kg^{-2})$
Spherical balls of radius R are falling in a viscous fluid of viscosity $ \eta $ with a velocity v. The retarding viscous force acting on the spherical ball is
In radioactive decay process, the negatively charged emitted (3-particles are
A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement $ x $ is proportional to
Three point charges $ +\,q,-2q $ and $ +q $ are placed at points $ (x=0,y=a,z=0), $ $ (x=0,y=0,z=0) $ and $ (x=a,y=0,z=0), $ respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are