Physics Test 3...

An object 2.4 m in front of a lens forms a sharp image on a film 12 cm behind the lens. A glass plate 1 cm thick, of refractive index 1.50 is interposed between lens and film with its plane faces parallel to film. At what distance (from lens) should object shifted to be in sharp focus on film?

Hydrogen atom is excited from ground state to another state with principal quantum number equal to 4. Then, the number of spectral lines in the emission spectra will be

Assume that a neutron breaks into a proton and an electron. The energy released during this process is (mass of neutron = 1.6725 × 10^-27 kg, mass of proton = 1.6725 × 10^-27 kg, mass of electron = 9 × 10^-31 kg)

A thin liquid film formed between a U-shaped wire and a light slider supports a weight of  15 × 10^-2 N (see figure). The length of the slider is 30 cm and its weight negligible. The surface tension of the liquid film is

A screw gauge gives the following reading when used to measure the diameter of a wire. , 
Main scale reading : 0 mm; Circular scale reading : 52 divisions  , 
Given that 1 mm on main scale corresponds to 100 divisions of the circular scale. The diameter of wire from the above data is

Two electric bulbs marked 25 W-220 V and 100 W-220 V are connected in series to a 440 V supply. Which of the bulbs will fuse?