1
AP EAPCET 2025 - 22nd May Morning Shift
MCQ (Single Correct Answer)
+1
-0

The difference between the frequencies of second and first Paschen lines of hydrogen atom is ( $R=$ Rydberg constant and $c=$ speed of light in vacuum)

A

$\frac{9 R c}{16}$

B

$\frac{16 R c}{25}$

C

$\frac{9 R c}{400}$

D

$\frac{3 R c}{200}$

2
AP EAPCET 2025 - 22nd May Morning Shift
MCQ (Single Correct Answer)
+1
-0

If the time taken for a radioactive substance to decay $8 \%$ to $77 \%$ is 12 minutes, then the half life of the substance in minutes is

A

24

B

18

C

12

D

6

3
AP EAPCET 2025 - 22nd May Morning Shift
MCQ (Single Correct Answer)
+1
-0
A transistor has 3 impurity regions of different doping levels. In the order of increasing doping level, the regions are
A

emitter, base, collector

B

collector, base, emitter

C

base, emitter, collector

D

base, collector, emitter

4
AP EAPCET 2025 - 22nd May Morning Shift
MCQ (Single Correct Answer)
+1
-0

A camera is fabricated using a semiconducting material having a band gap of 3 eV . The wavelength of light if can detect is nearly

A

210 nm

B

546 nm

C

413 nm

D

345 nm