Two electric bulbs A and B rated 200 V~100 W and 200 V~60 W are connected in series to a 200 V line. Then the potential drop across
The drift velocity of free electron in a metal wire of a given potential gradient along it is Vd. If this potential gradient is doubled the new drift velocity will be
In a potentiometer experiment, the balancing length for a cell was found to be 1.20 m. Now, a resistance of 10 
is connected across the terminals of this cell and the balancing length becomes 80 cm. The internal resistance of this cell is
A voltmeter has resistance 2000 and range 0-5 V. For increasing its range upto 20 V, a resistance of
A voltmeter has resistance 2000 and range 0-5 V. For increasing its range upto 20 V, a resistance of
An ammeter and a milliammeter are converted from identical galvanometers. Which one has smaller resistance?
The current i through a given cross-section varies with time t as i = 3 + 2t, where i is in ampere and t is in second. The charge passed through this cross-section during t = 0 to t = 2 s is
The transition from the state n = 4 to n = 3 in a hydrogen like atom results in ultraviolet radiation.Infrared radiation will be obtained in the transition from
Let 
be the charge density distribution for a solid sphere of radius R and total charge Q. For a point ‘p’ inside the sphere at distance r1 from the centre of the sphere, what will be the magnitude of electric field?
A thin uniform rod of length l and mass m is swinging freely about a horizontal axis passing through its end. Its maximum angular speed is ω. What will be its centre of mass rises to maximum height?
In an optics experiment, with the position of the object fixed, a student varies the position of a convex lens and for each position, the screen is adjusted to get a clear image of the object. A graph between the object distance u and the image distance v, from the lens, is plotted using the same scale for the two axes. A straight line passing through the origin and making an angle of 45° with the x-axis meets the experimental curve at P. What will be the coordinates of P?
If x, v and a denote the displacement, the velocity and the acceleration of a particle executing simple harmonic motion of time period T, then, which of the following does not change with time?
The logic circuit shown below has the input waveforms ‘A’ and ‘B’ as shown. Pick out the correct output waveform
What will be the output?
A p-n junction (D) shown in the figure can act as a rectifier.
An alternating current source (V) is connected in the circuit. The current (I) in the resistor (R) can be shown by
In the Young's double slit experiment, when a glass plate ( 
= 1.5) of thickness t is introduced in the path of one of the interfering beams (wavelength = 
), the intensity at the position where central maxima occurred previous remains unchanged. The minimum thickness of the glass plate is
Four harmonic waves of equal frequencies and equal intensities I0 have phase angles 
. When they are superposed, the intensity of the resulting wave is 
. The value of n is
In a Young's double slit experiment, 12 fringes are observed to be formed in a certain segment of the screen when light of wavelength 600 nm is used. If the wavelength of light is changed to 400 nm, number of fringes observed in the same segment of the screen is given by
In YDSE, d = 
, then the total no. of maxima observed upon screen will be
Young's double slit experiment is carried out by using green, red and blue light, one color at a time. The fringe widths recorded are
, respectively. Then,
In the Young's double slit experiment using a monochromatic light of wavelength , the path difference (in terms of an integer n) corresponding to any point having half the peak intensity is
If the amplitude ratio of two sources producing interference is 3 : 5, the ratio of intensities of maxima and minima is
For destructive interference to take place between two monochromatic light waves of wavelength 
, the path difference should be
Two identical light waves, propagating in the same direction, have a phase difference 
. After they superpose, the intensity of the resulting wave will be proportional to
Two coherent monochromatic light beams of intensites I and 4I are superimposed. The maximum and minimum possible intensities in the resulting beam are
The above is a plot of binding energy per nucleon Eb, against the nuclear mass M; A, B, C, D, E, F correspond to different nuclei. Consider four reactions:
where ε is the energy released? In which reactions is ε positive?
A piece of wire is bent in the shape of a parabola y = kx2 (y-axis vertical) with a bead of mass m on it. The bead can slide on the wire without friction. It stays at the lowest point of the parabola when the wire is at rest. The wire The wire is now accelerated parallel to the x-axis with a constant acceleration a. The distance of the new equilibrium position of the bead, where the bead can stay at rest w.r.t. the wire, from the y-axis is
What is the angle of friction between two surfaces in contact, if coefficient of friction is 
A force of 49 N is just able to move a block of wood weighing 10 kg on a rough horizontal surface, then coefficient of friction is
A block of mass 2 kg rests on an inclined plane of inclination angle 37o, then calculate the force of friction acting on the block [take g = 10 m/s2]
A particle of mass m is moving on a circular path of radius r with uniform speed v, rate of change of linear momentum is
A circular track of radius 600 m is to be designed for vehicles passing at an average speed of 54 km/hr. The required angle of banking is :
A block of mass 2 kg rests on the floor of an elevator, which is moving down with an acceleration ‘g’, then the apparent weight of the block is [take g = 10 m/s2]20
When a lift is moving upward with acceleration of 5 m/s2 then percentage change in the weight of the person in the lift is x%. If the lift is moving down with acceleration 5 m/s2 then percentage change in the weight of
same person is y%. Then the ratio x/y is (g = 10 m/s2)
A block is placed on a smooth inclined plane as shown. For what value of horizontal force F, the block will remain at rest?
Which of the following ion has the maximum magnetic moment?
The radius of 5th Bohr orbit in hydrogen atom is
Which of the following has the same number of s-electrons as the d-electrons in Fe2+?
Which of the following equation was suggested by de Broglie?
The momentum of a particle which has a de Broglie wavelength of 0.1 nm is (h = 6.6 × 10^-34 Js)
The total number of orbitals in a shell with principal quantum number n is
How many 3d electrons can have spin quantum number -1/2 ?
Which of the following represent(s) the correct set of four quantum numbers of a 4d electron?
The electron identified by quantum numbers n and /
(i) n=4,/=1 (ii) n=4,/=0, (iii) n= 3,/=0 (v) n=3,/= 1
Can be placed in order of increasing energy
The correct set of quantum numbers for the unpaired electron of chlorine atom is
The total number of electrons in a 4d subshell are
Which set of quantum numbers is not consistent with theory?
In the emission line spectra of hydrogen atom, how many lines can be accounted for all possible electronic transitions from 5th energy level within the atom?
The potential energy of an electron in hydrogen atom is -3.02 eV, its kinetic energy will be
The maximum number of electrons possible in subshell is equal to
How many electrons with / = 2 are there in an atom having atomic number 54?
Out of X-rays, infrared rays, visible rays and microwaves, the largest frequency is of