Semiconductor Electronic: Material, Devices And Simple Circuits — Physics STD 12 Science — Question

X−ray falling on a material.

Using visible light what is the shortest wavelength which can be measured?

If  and   are the wavelengths of characteristic X-rays and gamma rays respectively, then the relation between them is

(a)

(b)

(c)

(d)

Total internal reflection of a ray of light is possible when the ( = critical angle, i  =  angle of incidence)

(a) Ray goes from denser medium to rarer medium and

(b) Ray goes from denser medium to rarer medium and

(c) Ray goes from rarer medium to denser medium and

(d) Ray goes from rarer medium to denser medium and

The capacitance of a spherical condenser is 1μF. If the spacing between the two spheres is 1mm, then the radius of the outer sphere is

(a) 30 cm

(b) 6 m

(c) 5 cm

(d) 3 m

Which radiation in sunlight, causes heating effect

(a) Ultraviolet

(b) Infrared

(c) Visible light

(d) All of these

Let V and E be the gravitational potential and gravitational field at a distance r from the centre of a uniform spherical shell. Consider the following two statements:

1. The plot of V against r is discontinuous.
2. The plot of E against r is discontinuous.

1. Both A and B are correct.
2. A is correct but B is wrong.
3. B is correct but A is wrong.
4. Both A and B are wrong.

The radial magnetic field is used in a suspended coil galvanometer to provide:

A glass lens is placed in a medium in which it is found to behave like a glass plate. Refractive index of the medium will be

(a) Greater than the refractive index of glass

(b) Smaller than the refractive index of glass

(c) Equal to refractive index of glass

(d) No case will be possible from above

Which of the following is not equal to watt

(a)

(b) Amp / Volt

(c) Amp × Volt

(d) Joule / sec