Advertisements
Advertisements
A stone of mass 5 kg. tied to one end of a rope of length 0.8 m, is whirled in a vertical circle. Find the minimum velocity at the highest point and at the midway point.
[g = 9.8 m/s2]
Concept: undefined >> undefined
Let velocity of a sound wave be 'v' and 'ω' be angular velocity. The propagation constant of the wave is .................................
- `sqrt(omega/v)`
- `sqrt(v/omega)`
- `omega/v`
- `v/omega`
Concept: undefined >> undefined
Advertisements
Six capacitors of capacities 5, 5. 5, 5, 10 and X μ F are connected as shown in the network in the diagram.
Find :
- The value of X if the network is balanced, and
- The resultant capacitance between A and C.

Concept: undefined >> undefined
Explain the phenomenon of self induction
Concept: undefined >> undefined
Draw a neat labelled diagram for Ferry's perfectly black body.
Concept: undefined >> undefined
Let 'p' and 'E' denote the linear momentum and energy of emitted photon respectively. If the wavelength of incident radiation is increased ___ .
(a) both p and E increase
(b) p increases and E decreases
(c) p decreases and E increases
(d) both p and E decrease.
Concept: undefined >> undefined
In case of transistor oscillator, to obtain sustained oscillations, the product of voltage gain without feedback and feedback factor should be __________.
Concept: undefined >> undefined
Show graphical representation of energy distribution spectrum of perfectly black body.
Concept: undefined >> undefined
The wavelength range of thermal radiation is
(A) from 4000 Å to 7000 Å
(B) from 7700 Å to 4 x 106 Å
(C) from 106 Å to 108 Å
(D) from 4 x 10-12 Å to 4 x 108 Å
Concept: undefined >> undefined
If the difference in velocities of light in glass and water is 2.7 x 107 m/s, find the velocity of light in air. (Refractive index of glass = 1.5, Refractive index of water = 1.333)
Concept: undefined >> undefined
When electron in hydrogen atom jumps from second orbit to first orbit, the wavelength of radiation emitted is λ. When electron jumps from third orbit to first orbit, the wavelength of emitted radiation would be _______.
(A)`27/32lambda`
(B)`32/27lambda`
(C)`2/3lambda`
(D)`3/2lambda`
Concept: undefined >> undefined
Find the wavelength at which a black body radiates maximum energy, if its temperature is 427°C.
(Wein’s constant b = 2.898 × 10-3 mK)
(A) 0.0414 × 10-6m
(B) 4.14 × 10-6m
(C) 41.4 × 10-6m
(D) 414 × 10-6m
Concept: undefined >> undefined
If A.C. voltage is applied to a pure capacitor, then voltage across the capacitor _____________.
Concept: undefined >> undefined
State and prove Kirchoff’s law of heat radiation.
Concept: undefined >> undefined
Find the ratio of longest wavelength in Paschen series to shortest wavelength in Balmer series.
Concept: undefined >> undefined
The speed limit for a vehicle on road is 120 km/ hr. A policeman detects a drop of 10% in the pitch of horn of a car as it passes him. Is the policeman justified in punishing the car driver for crossing the speed limit? (Given: Velocity of sound= 340 m/s)
Concept: undefined >> undefined
In hydrogen atom Balmer series is obtained when the electron jumps from ............ .
(a) higher orbit to first orbit
(b) first orbit to a higher orbit
(c) higher orbit to the second orbit
(d) second orbit to a higher orbit
Concept: undefined >> undefined
What is de Broglie wavelength of an electron accelerated through 25000 volt?
Concept: undefined >> undefined
Light of wavelength 3000Å falls on a metal surface having work function 2.3 eV. Calculate the maximum velocity of ejected electrons
(Planck's constant h = 6.63 x 10-34 J.s., Velocity of light c = 3 x 108 m/s, mass of an electron = 9.1 x 10-31 kg)
Concept: undefined >> undefined
With the help of a neat diagram, describe the construction and working of van de Graff generator.
Concept: undefined >> undefined
