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

A proton, a deuteron and an α - particle having the same kinetic energy are moving in circular trajectories in a constant magnetic field. If   and   denote respectively the radii of the trajectories of these particles, then

(a)

(b)

(c)

(d)

Diffraction effects are easier to notice in the case of sound waves than in the case of light waves because

(a) Sound waves are longitudinal	(b) Sound is perceived by the ear
(c) Sound waves are mechanical waves	(d) Sound waves are of longer wavelength

Two charged spheres of radii R, and R2 are connected by a wire. The ratio of the electric fields of the spheres is:

Copper has face centered cubic (fcc) lattice with interatomic spacing equal to 2.54Å. The value of the lattice constant for this lattice is

(a) 1.27 Å

(b) 5.08 Å

(c) 2.54 Å

(d) 3.59 Å

5 amperes of current is passed through a metallic conductor. The charge flowing in one minute in coulombs will be

(a) 5

(b) 12

(c) 1/12

(d) 300

A particle with charge q, moving with a momentum p, enters a uniform magnetic field normally. The magnetic field has magnitude B and is confined to a region of width d, where d <  , The particle is deflected by an angle θ in crossing the field

(a) sinθ =

(b) sinθ =

(c) sinθ =

(d) sinθ =

Which of the following sets cannot enter into the list of fundamental quantities in any system of units?

1. Length, mass and velocity.
2. Length, time and velocity.
3. Mass, time and velocity.
4. Length, time and mass.

A convex mirror of focal length f forms an image which is   times the object. The distance of the object from the mirror is

(a) (n – 1)f

(b)

(c)

(d) (n + 1)f

A convex lens of focal length f  is placed somewhere in between an object and a screen. The distance between the object and the screen is x. If the numerical value of the magnification produced by the lens is m, then the focal length of the lens is

(a)

(b)

(c)

(d)