1
AP EAPCET 2025 - 21st May Evening Shift
MCQ (Single Correct Answer)
+1
-0

For an observer on the Earth, if a spectral line of wavelength $6600\mathop {\rm{A}}\limits^{\rm{o}}$ emitted by a star is found to be red shifted by $22 \mathop {\rm{A}}\limits^{\rm{o}}$, then the star is

A

receding away from Earth with a speed of $9 \times 10^5 \mathrm{~ms}^{-1}$

B

receding away from Earth with a speed of $10 \times 10^5 \mathrm{~ms}^{-1}$

C

moving towards Earth with a speed of $9 \times 10^5 \mathrm{~ms}^{-1}$

D

moving towards Earth with a speed of $10 \times 10^5 \mathrm{~ms}^{-1}$

2
AP EAPCET 2025 - 21st May Evening Shift
MCQ (Single Correct Answer)
+1
-0

Three particles of each charge $q$ are placed at the vertices of an equilateral triangle of side $L$. The work to be done to decrease the side of the triangle to $\frac{L}{2}$ is

A

$\frac{1}{4 \pi \varepsilon_0} \frac{q^2}{L}$

B

$\frac{1}{4 \pi \varepsilon_0} \frac{2 q^2}{L}$

C

$\frac{1}{4 \pi \varepsilon_0} \frac{3 q^2}{L}$

D

$\frac{1}{4 \pi \varepsilon_0} \frac{3 q^2}{2 L}$

3
AP EAPCET 2025 - 21st May Evening Shift
MCQ (Single Correct Answer)
+1
-0

The radii of the inner and outer spheres of a spherical capacitor are 8 cm and 9 cm respectively. The outer sphere is earthed and the inner sphere is charged. If the space between the concentric spheres is filled with a liquid of dielectric constant 5 , the capacitance of the capacitor is

A

400 PF

B

40 PF

C

$400 \mu \mathrm{~F}$

D

$40 \mu \mathrm{~F}$

4
AP EAPCET 2025 - 21st May Evening Shift
MCQ (Single Correct Answer)
+1
-0

If 27 charged water droplets, each of radius $10^{-3} \mathrm{~m}$ and charge $10^{-12} \mathrm{C}$ coalesce to form a single big spherical drop, then the potential of the big drop is

A

9 V

B

27 V

C

39 V

D

81 V