A point moves along the x axis according to the law x = a sin^2 (wt— π/4). Find:
(a) the amplitude and period of oscillations; draw the plot x (t);
(b) the velocity projection vx as a function of the coordinate x;draw the plot vx (x).
A point oscillates along the x axis according to the law x = a cos (wt — π/4). Draw the approximate plots (a) of displacement x, velocity projection vx, and acceleration projection wx as functions of time t; (b) velocity projection vx and acceleration projection wx as functions of the coordinate x.
Cellulose acetate is a?
Sum of real solutions of the equation 
is?
Number of integral values of a for which (a + 2)x*x + 2(a + 1) x + a = 0 will have integer roots is/are
Number of real ordered pair (x,y) satisfying x*x +1=y and y*y +1=x is?
Let p,q be roots of the equation x*x -4x+A=0 and r and s be the roots of the equation x*x -20x+B=0.If p < q < r < s are in A.P., then (A, B) is
The number of integral value(s) of x satisfying the equation 
The least integral value of 'a' such that (a-2)x*x +8x+a+4>0, 
The set of values of 'p' so that both the roots of the equation (p-5)x*x -2px +(p-4)= 0 are positive,one is less than 2 and other is lying between 2 & 3, is
The number of integral values of ëmí less than 50 , so that the roots of the quadratic equation mx2 +(2m-1)x+(m-2)=0 are rational,are
if 
are the roots of the equation 
the equation whose roots are 
is
If a, b, c 
and the quadratic equation 
has no real roots, then
The binding energy per nucleon of deuteron 
and helium nucleus 
is 1.1 MeV and 7 MeV respectively. If two deuteron nuclei react to form a single helium nucleus, then the energy released is
A nucleus disintegrates into two nuclear parts which have their velocities in the ratio 2 : 1. What would be the ratio of their nuclear sizes?
If the binding energy of the electron in a hydrogen atom is 13.6 eV, the energy required to remove the electron from the first excited state of Li++ is
The wavelengths involved in the spectrum of deuterium 
are slightly different from that of hydrogen spectrum, because
Which of the following atoms has the lowest ionization potential?
In the nuclear fusion reaction,
given that the repulsive potential energy between the two nuclei is ~ 7.7 × 10-14 J, the temperature at which the gases must be heated to initiate the reaction is nearly
Note: Boltzmann's constant k = 1.38 × 10-23 J/K
Which of the following cannot be emitted by radioactive substances during their decay?
A nucleus with Z = 92 emits the following in a sequence: 
The Z of the resulting nucleus is
A radioactive sample at any instant has its disintegration rate 5000 disintegrations per minute. After 5 minutes, the rate is 1250 disintegrations per minute. Then, what will be the decay constant (per minute)?
When U238 nucleus originally at rest, decays by emitting an alpha particle having a speed u, the recoil speed of the residual nucleus is
Which of the following radiations has the least wavelength?
If N0 is the original mass of the substance of half life period t1/2 = 5 years, then the amount of substance left after 15 years is
If 13.6 eV energy is required to ionize the hydrogen atom, then the energy required to remove an electron from n = 2 is
At a specific instant emission of a radioactive compound is deflected in a magnetic field. The compound can emit
(i) electrons
(ii) protons
(iii) He2+
(iv) neutrons
The emission at the instant can be
If gE and gM are the accelerations due to gravity on the surfaces of the earth and the moon respectively and if Millikan’s oil drop experiment could be performed on the two surfaces, then what would be the ratio
Photon of frequency u has a momentum associated with it. If c is the velocity of light, the momentum is
The anode voltage of a photocell is kept fixed. The wavelength
of the light falling on the cathode is gradually changed. The plate current I of the photocell varies as follows
The threshold frequency for a metallic surface corresponds to an energy of 6.2 eV, and the stopping potential for a radiation incident on this surface 5 V. Where the incident radiation lies?
What is the time by a photoelectron to come out after the photon strikes approximately?
If the kinetic energy of a free electron doubles, its de Broglie wavelength changes by the factor
A photocell is illuminated by a small bright source placed 1 m away. When the same source of light is placed (1/2) m away, the number of electrons emitted by photocathode would
Explain Skull
Explain APPENDICULAR SKELETOM ?
AXIAL SKELETON
Types of HUMAN SKELETAL SYSTEM
Explain HUMAN SKELETAL SYSTEM
A charged oil drop is suspended in a uniform field of 3 × 104 V/m so that it neither falls nor rises. What will be the charge on the drop?
Note: mass of the charge = 9.9 × 10-15 kg and g = 10 m/s2
The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately
According to Einstein’s photoelectric equation, the plot of the kinetic energy of the emitted photo electrons from a metal vs the frequency, of the incident radiation gives a straight line whose slope
Two identical photocathodes receive light of frequencies f1 and f2. If the velocities of the photoelectrons (of mass m) coming out are respectively v1 and v2, then
Sodium and copper have work functions 2.3 eV and 4.5 eV respectively. Then what will be the ratio of the wavelengths?
The rms value of the electric field of the light coming from the sun is 720 N/C. The average total energy density of the electromagnetic wave is
An electromagnetic wave of frequency 
= 3.0 MHz passes from vacuum into a dielectric medium with permittivity 
= 4.0. Then
Consider telecommunication through optical fibres. Which of the following statements is not true?