In which of the following devices is the principle of photoelectric effect not applicable?
close-circuit television camera
burglar alarm
solar cells
periscope
Correct answer is D
No explanation has been provided for this answer.
An atom is normally electrically neutral because the
number of electrons is equal to the number of protons
number of electrons is equal to the number of neutrons
number of protons is equal to the number of neutrons
electrons of the atom are buried deeply in the nucleus
Correct answer is A
No explanation has been provided for this answer.
The main function of the mouth piece of a telephone is that it converts sound energy to
mechanical energy
electrical energy
chemical energy
thermal energy
Correct answer is B
No explanation has been provided for this answer.
3.2 x 105N
1.8 x 105N
3.2 x 10-5N
1.8 x 10-5N
Correct answer is C
F = Exq = 2.0 x 105 x 1.6 x 10-10
= 3.2 x 10-5N
\(Gr^2 M_1M_2\)
\(Gr M_1M_2\)
\(\frac{GM_1 M_2}{r^2}\)
\(\frac{GM_1 M_2}{r}\)
Correct answer is C
No explanation has been provided for this answer.