1
JEE Main 2023 (Online) 6th April Evening Shift
+4
-1

A 2 meter long scale with least count of $$0.2 \mathrm{~cm}$$ is used to measure the locations of objects on an optical bench. While measuring the focal length of a convex lens, the object pin and the convex lens are placed at $$80 \mathrm{~cm}$$ mark and $$1 \mathrm{~m}$$ mark, respectively. The image of the object pin on the other side of lens coincides with image pin that is kept at $$180 \mathrm{~cm}$$ mark. The $$\%$$ error in the estimation of focal length is:

A
1.70
B
0.51
C
1.02
D
0.85
2
JEE Main 2023 (Online) 6th April Morning Shift
+4
-1

A monochromatic light wave with wavelength $$\lambda_{1}$$ and frequency $$v_{1}$$ in air enters another medium. If the angle of incidence and angle of refraction at the interface are $$45^{\circ}$$ and $$30^{\circ}$$ respectively, then the wavelength $$\lambda_{2}$$ and frequency $$v_{2}$$ of the refracted wave are:

A
$$\lambda_{2}=\lambda_{1}, v_{2}=\frac{1}{\sqrt{2}} v_{1}$$
B
$$\lambda_{2}=\lambda_{1}, v_{2}=\sqrt{2} v_{1}$$
C
$$\lambda_{2}=\sqrt{2} \lambda_{1}, v_{2}=v_{1}$$
D
$$\lambda_{2}=\frac{1}{\sqrt{2}} \lambda_{1}, v_{2}=v_{1}$$
3
JEE Main 2023 (Online) 1st February Evening Shift
+4
-1

Two objects A and B are placed at 15 cm and 25 cm from the pole in front of a concave mirror having radius of curvature 40 cm. The distance between images formed by the mirror is _______________.

A
60 cm
B
40 cm
C
160 cm
D
100 cm
4
JEE Main 2023 (Online) 31st January Evening Shift
+4
-1
A microscope is focused on an object at the bottom of a bucket. If liquid with refractive index $\frac{5}{3}$ is poured inside the bucket, then the microscope has to be raised by $30 \mathrm{~cm}$ to focus the object again. The height of the liquid in the bucket is :
A
$50 \mathrm{~cm}$
B
$18 \mathrm{~cm}$
C
$75 \mathrm{~cm}$
D
$12 \mathrm{~cm}$
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Medical
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