Electric Charges and Fields — Physics STD 12 Science — Question

de-Broglie wavelength of a body of mass 1 kg moving with velocity of 2000 m/s is

(a) 3.32 × 10–27 Å

(b) 1.5 × 107 Å

(c) 0.55 × 10–22 Å

(d) None of these

Carbon, silicon and germanium have four valence electrons each. At room temperature the appropriate statement is:

The similarity between the sound waves and light waves is

(a) Both are electromagnetic waves

(b) Both are longitudinal waves

(c) Both have the same speed in a medium

(d) They can produce interference

If the frequency of light in a photoelectric experiment is doubled, the stopping potential will:

Which of the following is correct statement:

If potential  V = 100 ± 0.5 Volt and current I = 10  ± 0.2 amp are given to us.  Then what will be the value of resistance

(a) 10 ± 0.7 ohm

(b) 5 ± 2 ohm

(c) 0.1 ± 0.2 ohm

(d) None of these

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 =

Wave which cannot travel in vacuum is

(a) X-rays

(b) Infrasonic

(c) Ultraviolet

(d) Radiowaves

The energy required to excite an electron from the ground state of hydrogen atom to the first excited state, is

(a) 1.602

(b) 1.619

(c) 1.632

(d) 1.656

Which principle suggests that the intensity of light determines its amplitude?