Electricity
Current Electricity
MCQ (Single Correct Answer)
Moving Charges and Magnetism
MCQ (Single Correct Answer)
Magnetism and Matter
MCQ (Single Correct Answer)
Electromagnetic Induction
MCQ (Single Correct Answer)
Electromagnetic Waves
MCQ (Single Correct Answer)
Modern Physics
Semiconductor Electronics
MCQ (Single Correct Answer)
1
NEET 2021
MCQ (Single Correct Answer)
+4
-1
An electromagnetic wave of wavelength '$$\lambda$$' is incident on a photosensitive surface of negligible work function. If 'm' mass is of photoelectron emitted from the surface has de-Broglie wavelength $$\lambda$$d, then :
A
$$\lambda = \left( {{{2h} \over {mc}}} \right){\lambda _d}^2$$
B
$$\lambda = \left( {{{2m} \over {hc}}} \right){\lambda _d}^2$$
C
$${\lambda _d} = \left( {{{2mc} \over h}} \right){\lambda ^2}$$
D
$$\lambda = \left( {{{2mc} \over h}} \right){\lambda _d}^2$$
2
NEET 2020 Phase 1
MCQ (Single Correct Answer)
+4
-1
Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled?
A
four times
B
one-fourth
C
zero
D
doubled
3
NEET 2020 Phase 1
MCQ (Single Correct Answer)
+4
-1
Light with an average flux of 20 W/cm2 falls on a non-reflecting surface at normal incidence having surface area 20 cm2. The energy received by the surface during time span of 1 minute is :
A
12 $$ \times $$ 103 J
B
24 $$ \times $$ 103 J
C
48 $$ \times $$ 103 J
D
10 $$ \times $$ 103 J
4
NEET 2020 Phase 1
MCQ (Single Correct Answer)
+4
-1
An electron is accelerated from rest through a potential difference of V volt. If the de-Broglie wavelength of the electron is 1.227 $$ \times $$ 10-2 nm, the potential difference is :
A
102 V
B
103 V
C
104 V
D
10 V
NEET Subjects