1
JEE Main 2024 (Online) 4th April Morning Shift
+4
-1

Which figure shows the correct variation of applied potential difference (V) with photoelectric current (I) at two different intensities of light $$(\mathrm{I}_1<\mathrm{I}_2)$$ of same wavelengths :

A
B
C
D
2
JEE Main 2024 (Online) 1st February Evening Shift
+4
-1
Monochromatic light of frequency $6 \times 10^{14} \mathrm{~Hz}$ is produced by a laser. The power emitted is $2 \times 10^{-3} \mathrm{~W}$.

How many photons per second on an average, are emitted by the source ?

(Given $\mathrm{h}=6.63 \times 10^{-34} \mathrm{Js}$ )
A
$5 \times 10^{15}$
B
$7 \times 10^{16}$
C
$6 \times 10^{15}$
D
$9 \times 10^{18}$
3
JEE Main 2024 (Online) 1st February Evening Shift
+4
-1
Conductivity of a photodiode starts changing only if the wavelength of incident light is less than $660 \mathrm{~nm}$. The band gap of photodiode is found to be $\left(\frac{\mathrm{X}}{8}\right) \mathrm{eV}$. The value of $\mathrm{X}$ is :

(Given, $\mathrm{h}=6.6 \times 10^{-34} \mathrm{Js}, \mathrm{e}=1.6 \times 10^{-19} \mathrm{C}$ )
A
11
B
13
C
15
D
21
4
JEE Main 2024 (Online) 1st February Morning Shift
+4
-1
The de Broglie wavelengths of a proton and an $\alpha$ particle are $\lambda$ and $2 \lambda$ respectively. The ratio of the velocities of proton and $\alpha$ particle will be :
A
$8: 1$
B
$1: 2$
C
$1: 8$
D
$4: 1$
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