An electric dipole is placed at an alignment angle of 30^o with an electric field of 2 x 10⁵ NC^-1. It experiences a torque equal to 8 N m. The charge on the dipole if the dipole length is 1 cm is

Two identical conducting balls having positive charges q₁ and q₂ are separated by a centre to centre distance r. If they are made to touch each other and then separated to the same distance, the force between them will be _____.

Two identical coils, each with N turns and radius R are placed coaxially at a distance R as shown in the figure. If I is the current passing through the loops in the same direction, then the magnetic field at a point P at a distance of R/2 from the centre of each coil is _____.
 

A thin semi-circular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in the figure.

The potential difference developed across the ring when its speed v, is

An inductor 20 mH, a capacitor 50 μF and a resistor 40Ω are connected in series across a source of emf V = 10 sin 340 t. The power loss in AC circuit is

The electric and magnetic fields of an electromagnetic wave are _____.

When a metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2λ, the stopping potential is \(\frac{V}{4}\). The threshold wavelength for the metallic surface is _____.

The nucleus is approximately spherical in shape. Then the surface area of nucleus having mass number A varies as _____.

The principle used for 'transmission of light signals through optical fibre is ________.

In actual practice, the range of uplink frequencies used is _________ GHz.

Heavily doped region of a transistor is ___________

Supplier of majority charge carriers in a transistor is ______

Acceptor of majority charge carriers in a transistor is ___________

The collector-base junction of a transistor offers _________ resistance to current

ln NPN transistors, when the emitter-base junction is forward-biased, the direction of conventional current is from _____________

Define electrical conductivity of a conductor. On what factor does it depend?

Which ray has high ionising power? Why?

What is meant by correspoding points?

What is forbidden energy gap?

What is conduction band?

What is transducer?

What is the radius of the illumination when seen above from inside a swimming pool from a depth of 10 m on a sunny day? What is the total angle of view? [Given, refractive index of water is 4/3]

If the focal length is 150 cm for a lens, what is the power of the lens?

Calculate the average atomic mass of chlorine if no distinction is made between its different isotopes?

Discuss the applications of Nanomaterials in various fields.

Explain the construction and working of a full wave rectifier

State Boolean laws. Elucidate how they are used to simplify Boolean expressions with suitable example.

Write the application of alpha decay in smoke detectors.

Express one joule in eV. Taking 1 amu = 931 MeV. Calculate the mass of C-12 atom.

You are given two converging lenses of focal lengths 1.25 cm and 5 cm to design a compound microscope. If it is desired to have a magnification of 30, find out the separation between the objective and the eyepiece.

In Young's experiment, the upper slit is covered by a thin glass plate of refractive index 1.4 while the lower slit is covered by another glass plate having the same thickness as the first one but having refractive index 1.7. Interference pattern is observed using light of wavelength 5400 Å. It is observed that the point P on the screen where the central maximum (n = 0) fell before the glass were inserted now has \(\cfrac { 3 }{ 4 } \) th original intensity. It is further observed that what used to be the fifth maximum earlier, lies below the point P while the sixth minimum lies above P. Calculate the thickness of the glass plate.

For a BJT circuit shown, assume that the 'β' of the transistor is very large and V_BE= 0.7 V. The mode of operation.