Atoms — Physics STD 12 Science — Question

Which of the following are in the ascending order of wavelength?

What is the ratio of the speed of infrared and ultraviolet rays in a vacuum?

The wavefront is a surface in which:

The logic behind ‘NOR’ gate is that it gives

(a) High output when both the inputs are low

(b) Low output when both the inputs are low

(c) High output when both the inputs are high

(d) None of these

‘X’ is a type of commercial resistor made from a mixture of clay, carbon black, and resin binder which are pressed and then molded into cylindrical rods by heating. Identify X.

A capacitor when filled with a dielectric K = 3  has charge , voltage  and field . If the dielectric is replaced with another one having K = 9  the new values of charge, voltage and field will be respectively

(a)

(b)

(c)

(d)

If the decay or disintegration constant of a radioactive substance is λ, then its half life and mean life are respectively

(a)  and

(b) and

(c)  and

(d)  and

A) Line spectra is due to atoms in gaseous state:
B) Band spectra is due to molecules:

There are  n similar conductors each of resistance R. The resultant resistance comes out to be  x when connected in parallel. If they are connected in series, the resistance comes out to be

(a)

(b)

(c) x/n

(d) nx

Sixty-four drops are jointed together to form a bigger drop. If each small drop has a capacitance C, a potential V, and a charge q, then the capacitance of the bigger drop will be

(a) C

(b) 4C

(c) 16C

(d) 64C