List of practice Questions

In the Young's double- slit experiment, the intensity of light at a point on the screen where the path difference is λ is K, (λ being the wave length of light used). The intensity at a point where the path difference is \(\frac{λ}{4}\), will be:

The force F acting on a particle of mass m is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from zero to 8s is

The ratio of the accelerations for a solid sphere (mass 'm' and radius 'R') rolling down an incline of angle 'θ' without slipping and slipping down the incline without rolling is:

A beam of light of λ = 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between first dark fringes on either side of the central bright fringe is:

If force (F), velocity (V) and time (T) are taken as fundamental units, then the dimensions of mass are:

If the kinetic energy of the particle is increased to 16 times its previous value, the percentage change in the de-Broglie wavelength of the particle is :

In a region, the potential is represented by V(x, y, z) = 6x-8xy-8y+6yz, where V is in volts and x, y, z are in meters. The electric force experienced by a charge of 2 coulomb situated at point (1, 1, 1) is:

Light with an energy flux of 25 × 10⁴ Wm^-2 falls on a perfectly reflecting surface at normal incidence. If the surface area is 15 cm², the average force exerted on the surface is:

The barrier potential of a p-n junction depends on:
(a) type of semi conductor material
(b) amount of doping
(c) temperature
Which one of the following is correct?

The Binding energy per nucleon of \(^7_3Li\) and \(^4_2He\) nuclei are 5.60 MeV and 7.06 MeV, respectively. In the nuclear reaction \(^7_3Li + ^1_1H \rightarrow ^4_2He + ^4_2He+Q\), the value of energy Q released is:

Dependence of intensity of gravitational field (E) of earth with distance (r) from centre of earth is correctly represented by

If the focal length of objective lens is increased then magnifying power of:

The angle of a prism is 'A'. One of its refracting surfaces is silvered. Light rays falling at an angle of incidence 2A on the first surface returns back through the same path after suffering reflection at the silvered surface. The refractive indexµ, of the prism is

The given graph represents V – I characteristic for a semiconductor device

Which of the following statement is correct?

The number of possible natural oscillations of air column in a pipe closed at one end of length 85 cm whose frequencies lie below 1250Hz are: (velocity of sound = 340 ms^-1)

The oscillation of a body on a smooth horizontal surface is represented by the equation,
X = A cos (ωt)
where X = displacement at time t
        ω = frequency of oscillation
Which one of the following graphs shows correctly the variation 'a' with 't'?
Here a acceleration at time t
T = time period

Two cities are 150 km apart. Electric power is sent from one city to another city through copper wires. The fall of potential per km is 8 volt and the average resistance per km is 0.5Ω. The power loss in the wire is:

A thin semicircular conducting ring (PQR) of radius 'r' is falling with its plane vertical in a horizontal magnetic field B, as shown in figure. The potential difference developed across the ring when its speed is v, is:

Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole moment \(\overrightarrow{m}\). Which configuration has highest net magnètic dipole moment?

In an ammeter 0.2% of main current passes through the galvanometer. If resistance of galvanometer is G, the resistance of ammeter will be:

Two identical long conducting wires AOB and COD are placed at right angle to each other, with one above other such that 'O' is their common point for the two. The wires carry I₁ and I₂ currents, respectively. Point 'P' is lying at distance 'd' from 'O' along a direction perpendicular to the plane containing the wires. The magnetic field at the point 'P' will be:

A conducting sphere of radius R is given a onducting charge Q. The electric potential and the electric field at the centre of the sphere respectively are:

A thermodynamic system undergoes cyclic process ABCDA as shown in Fig. The work done by the system in the cycle is:

Copper of fixed volume 'V' is drawn into wire of length 'l'. When this wire is subjected to a constant force 'F', the extension produced in the wire is 'Δl'. Which of the following graphs is a straight line?

If n₁, n₂ and n₃ are the fundamental frequencies of three segments into which a string is divided, then the original fundamental frequency n of the string is given by: