1 eV = ____ J. (Fill in the gap)

Electric field is always ______ to the equipotential surface at every point. (Fill in the gap)

1J = …………. calorie. (Fill up the blank)

A gaseous system absorbs 450 cal heat. The work done by the system is 836.2 J. Find the change in internal energy of the gas in calorie. (J=4.186 J "cal"^(-1) )

1 gcm^(-3).... Kgm^(-3) (Fill the gaps)

The following table shows certain diseases, their causative organisms and symptoms. Fill the gaps.

A p-n photodiode is made of a material with a band gap of 2.0 eV. The minimum frequency of the radiation that can be absorbed by the material is nearly ……

A beam of electromagnetic radiation intensity 6.4xx10^(-5)W//cm^(2) is comprised of wavelength , lambda =310 nm.It falls normally on metal (work function 2 eV) of surface are 1 cm^(2) .If one in 10^(3) photons ejects an electron ,total number of electrons ejected in 1 s is 10^x [hc=1240 eV-nm ,1 eV= 1.6xx10^(-19)J ],the value of x is....

A photon collides with a stationary hydrogen atom in ground state inelastically. Energy of the colliding photon is 10.2 eV. After a time interval of the order of micro second another photon collides with same hydrogen atom inelastically with an energy of 15eV. What wil be observed by the detector? (a) 2 photons of energy 10.2 eV (b) 2 photons of energy 1.4 eV (c ) One photon of energy 10.2 eV and an electron of energy 1.4 eV (d) One photon of energy 10.2 eV and another photon of energy 1.4 eV

Photons of energy 1 eV and 2.5 eV sucesseively illuminate a metal,whose work function is 0.5 eV,the ratio of maximum speed of emitted electron is…..

The wavelength of light in the visible region is about 390 nm for violet colour, about 550 nm (average wavelength) for yellowgreen colour and about 760 nm for red colour. (a) What are the energies of photons in (eV) at the (i) violet end, (ii) average wavelength, yellow-green colour, and (iii) red end of the visible spectrum? ("Take h "= 6.63xx10^(-34)" J s and 1 eV" = 1.6xx10^(-19)J.) (b) From which of the photosensitive materials with work functions listed in Table 11.1 and using the results of (i), (ii) and (iii) of (a), can you build a photoelectric device that operates with visible light?