281921
If a ray travelling in the direction $\frac{1}{2}(\hat{\mathbf{i}}+\sqrt{3} \hat{\mathbf{j}})$ is incident on a plane mirror. After reflection, the ray travels along the direction $\frac{1}{2}(\hat{i}-\sqrt{3} \hat{j})$. The angle of incidence is
1 $45^{\circ}$
2 $75^{\circ}$
3 $30^{\circ}$
4 $60^{\circ}$
Explanation:
C: Given, Incident direction $=\frac{1}{2}(\hat{i}+\sqrt{3} \hat{j})$
Reflected direction $=\frac{1}{2}(\hat{i}-\sqrt{3} \hat{j})$
Here, the direction of $x$ (i.e. $\hat{i})$ remains same while the direction of $y($ i.e. $\hat{j})$ change.
Hence, angle of incidence is angle between the unit vector $\frac{1}{2}(\hat{i}+\sqrt{3} \hat{j})$ and $\hat{j}$
$\begin{array}{l}
\therefore \quad \cos (i)=\frac{1}{2}(\hat{\mathrm{i}}+\sqrt{3} \hat{\mathrm{j}}) \cdot \hat{\mathrm{j}} \\
\mathrm{i}=\cos ^{-1}\left(\frac{\sqrt{3}}{2}\right) \\
\mathrm{i}=30^{\circ}
\end{array}$
CG PET-22.05.2022
Ray Optics
281922
A plane mirror is approaching you at $5 \mathrm{~cm} . \mathrm{s}^{-1}$. You can see your image in it. At what speed will your image approach you ?
1 $10 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
2 $5 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
3 $20 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
4 $15 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
Explanation:
A: Given, speed of mirror $(\mathrm{V})=5 \mathrm{~cm} / \mathrm{sec}$
Let, the distance between the object and the mirror be $\mathrm{d}$ As we know, image move 2 times faster than the mirror speed
Image speed $=2 \mathrm{~V}=2 \times 5=10 \mathrm{~cm} / \mathrm{sec}$
AP EAMCET-05.10.2021
Ray Optics
281923
An object is placed at a distance of $40 \mathrm{~cm}$ in front of a concave mirror of focal length $20 \mathrm{~cm}$. The image produced is
1 real, inverted and smaller in size
2 real, inverted and of same size
3 real and erect
4 virtual and inverted
Explanation:
B: Given, focal length (f) $=20 \mathrm{~cm}$ and object at a distance of $40 \mathrm{~cm}$ means object placed at centre of curvature Then,
Hence, the image produced is real inverted and of same size as that of object.
TS- EAMCET-09.09.2020
Ray Optics
281924
Assertion : Diamond glitters brilliantly.
Reason: Diamond does not absorb sunlight.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
B: Diamond glitters brilliantly due to total internal reflection occurring multiple times to light ray entering diamond.
NEET Test Series from KOTA - 10 Papers In MS WORD
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Ray Optics
281921
If a ray travelling in the direction $\frac{1}{2}(\hat{\mathbf{i}}+\sqrt{3} \hat{\mathbf{j}})$ is incident on a plane mirror. After reflection, the ray travels along the direction $\frac{1}{2}(\hat{i}-\sqrt{3} \hat{j})$. The angle of incidence is
1 $45^{\circ}$
2 $75^{\circ}$
3 $30^{\circ}$
4 $60^{\circ}$
Explanation:
C: Given, Incident direction $=\frac{1}{2}(\hat{i}+\sqrt{3} \hat{j})$
Reflected direction $=\frac{1}{2}(\hat{i}-\sqrt{3} \hat{j})$
Here, the direction of $x$ (i.e. $\hat{i})$ remains same while the direction of $y($ i.e. $\hat{j})$ change.
Hence, angle of incidence is angle between the unit vector $\frac{1}{2}(\hat{i}+\sqrt{3} \hat{j})$ and $\hat{j}$
$\begin{array}{l}
\therefore \quad \cos (i)=\frac{1}{2}(\hat{\mathrm{i}}+\sqrt{3} \hat{\mathrm{j}}) \cdot \hat{\mathrm{j}} \\
\mathrm{i}=\cos ^{-1}\left(\frac{\sqrt{3}}{2}\right) \\
\mathrm{i}=30^{\circ}
\end{array}$
CG PET-22.05.2022
Ray Optics
281922
A plane mirror is approaching you at $5 \mathrm{~cm} . \mathrm{s}^{-1}$. You can see your image in it. At what speed will your image approach you ?
1 $10 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
2 $5 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
3 $20 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
4 $15 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
Explanation:
A: Given, speed of mirror $(\mathrm{V})=5 \mathrm{~cm} / \mathrm{sec}$
Let, the distance between the object and the mirror be $\mathrm{d}$ As we know, image move 2 times faster than the mirror speed
Image speed $=2 \mathrm{~V}=2 \times 5=10 \mathrm{~cm} / \mathrm{sec}$
AP EAMCET-05.10.2021
Ray Optics
281923
An object is placed at a distance of $40 \mathrm{~cm}$ in front of a concave mirror of focal length $20 \mathrm{~cm}$. The image produced is
1 real, inverted and smaller in size
2 real, inverted and of same size
3 real and erect
4 virtual and inverted
Explanation:
B: Given, focal length (f) $=20 \mathrm{~cm}$ and object at a distance of $40 \mathrm{~cm}$ means object placed at centre of curvature Then,
Hence, the image produced is real inverted and of same size as that of object.
TS- EAMCET-09.09.2020
Ray Optics
281924
Assertion : Diamond glitters brilliantly.
Reason: Diamond does not absorb sunlight.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
B: Diamond glitters brilliantly due to total internal reflection occurring multiple times to light ray entering diamond.
281921
If a ray travelling in the direction $\frac{1}{2}(\hat{\mathbf{i}}+\sqrt{3} \hat{\mathbf{j}})$ is incident on a plane mirror. After reflection, the ray travels along the direction $\frac{1}{2}(\hat{i}-\sqrt{3} \hat{j})$. The angle of incidence is
1 $45^{\circ}$
2 $75^{\circ}$
3 $30^{\circ}$
4 $60^{\circ}$
Explanation:
C: Given, Incident direction $=\frac{1}{2}(\hat{i}+\sqrt{3} \hat{j})$
Reflected direction $=\frac{1}{2}(\hat{i}-\sqrt{3} \hat{j})$
Here, the direction of $x$ (i.e. $\hat{i})$ remains same while the direction of $y($ i.e. $\hat{j})$ change.
Hence, angle of incidence is angle between the unit vector $\frac{1}{2}(\hat{i}+\sqrt{3} \hat{j})$ and $\hat{j}$
$\begin{array}{l}
\therefore \quad \cos (i)=\frac{1}{2}(\hat{\mathrm{i}}+\sqrt{3} \hat{\mathrm{j}}) \cdot \hat{\mathrm{j}} \\
\mathrm{i}=\cos ^{-1}\left(\frac{\sqrt{3}}{2}\right) \\
\mathrm{i}=30^{\circ}
\end{array}$
CG PET-22.05.2022
Ray Optics
281922
A plane mirror is approaching you at $5 \mathrm{~cm} . \mathrm{s}^{-1}$. You can see your image in it. At what speed will your image approach you ?
1 $10 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
2 $5 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
3 $20 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
4 $15 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
Explanation:
A: Given, speed of mirror $(\mathrm{V})=5 \mathrm{~cm} / \mathrm{sec}$
Let, the distance between the object and the mirror be $\mathrm{d}$ As we know, image move 2 times faster than the mirror speed
Image speed $=2 \mathrm{~V}=2 \times 5=10 \mathrm{~cm} / \mathrm{sec}$
AP EAMCET-05.10.2021
Ray Optics
281923
An object is placed at a distance of $40 \mathrm{~cm}$ in front of a concave mirror of focal length $20 \mathrm{~cm}$. The image produced is
1 real, inverted and smaller in size
2 real, inverted and of same size
3 real and erect
4 virtual and inverted
Explanation:
B: Given, focal length (f) $=20 \mathrm{~cm}$ and object at a distance of $40 \mathrm{~cm}$ means object placed at centre of curvature Then,
Hence, the image produced is real inverted and of same size as that of object.
TS- EAMCET-09.09.2020
Ray Optics
281924
Assertion : Diamond glitters brilliantly.
Reason: Diamond does not absorb sunlight.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
B: Diamond glitters brilliantly due to total internal reflection occurring multiple times to light ray entering diamond.
281921
If a ray travelling in the direction $\frac{1}{2}(\hat{\mathbf{i}}+\sqrt{3} \hat{\mathbf{j}})$ is incident on a plane mirror. After reflection, the ray travels along the direction $\frac{1}{2}(\hat{i}-\sqrt{3} \hat{j})$. The angle of incidence is
1 $45^{\circ}$
2 $75^{\circ}$
3 $30^{\circ}$
4 $60^{\circ}$
Explanation:
C: Given, Incident direction $=\frac{1}{2}(\hat{i}+\sqrt{3} \hat{j})$
Reflected direction $=\frac{1}{2}(\hat{i}-\sqrt{3} \hat{j})$
Here, the direction of $x$ (i.e. $\hat{i})$ remains same while the direction of $y($ i.e. $\hat{j})$ change.
Hence, angle of incidence is angle between the unit vector $\frac{1}{2}(\hat{i}+\sqrt{3} \hat{j})$ and $\hat{j}$
$\begin{array}{l}
\therefore \quad \cos (i)=\frac{1}{2}(\hat{\mathrm{i}}+\sqrt{3} \hat{\mathrm{j}}) \cdot \hat{\mathrm{j}} \\
\mathrm{i}=\cos ^{-1}\left(\frac{\sqrt{3}}{2}\right) \\
\mathrm{i}=30^{\circ}
\end{array}$
CG PET-22.05.2022
Ray Optics
281922
A plane mirror is approaching you at $5 \mathrm{~cm} . \mathrm{s}^{-1}$. You can see your image in it. At what speed will your image approach you ?
1 $10 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
2 $5 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
3 $20 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
4 $15 \mathrm{~cm} \cdot \mathrm{s}^{-1}$
Explanation:
A: Given, speed of mirror $(\mathrm{V})=5 \mathrm{~cm} / \mathrm{sec}$
Let, the distance between the object and the mirror be $\mathrm{d}$ As we know, image move 2 times faster than the mirror speed
Image speed $=2 \mathrm{~V}=2 \times 5=10 \mathrm{~cm} / \mathrm{sec}$
AP EAMCET-05.10.2021
Ray Optics
281923
An object is placed at a distance of $40 \mathrm{~cm}$ in front of a concave mirror of focal length $20 \mathrm{~cm}$. The image produced is
1 real, inverted and smaller in size
2 real, inverted and of same size
3 real and erect
4 virtual and inverted
Explanation:
B: Given, focal length (f) $=20 \mathrm{~cm}$ and object at a distance of $40 \mathrm{~cm}$ means object placed at centre of curvature Then,
Hence, the image produced is real inverted and of same size as that of object.
TS- EAMCET-09.09.2020
Ray Optics
281924
Assertion : Diamond glitters brilliantly.
Reason: Diamond does not absorb sunlight.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
B: Diamond glitters brilliantly due to total internal reflection occurring multiple times to light ray entering diamond.
