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Aparna Sahu
Subject: Physics
, asked on 20/4/18
Solve this.
36. When a small lamp is held 1.5 m above the surface of water in a tank, its image formed by reflection as the surface appears to coincide with image of the bottom of the tank (
$\mu $
of water = 4/3). The depth of tank is
(a) 2 m
(b) 1.5 m
(c) 1 m
(d) 4 m
Answer
1
Aparna Sahu
Subject: Physics
, asked on 20/4/18
38. A telescope is adjusted for parallel rays. The distance between the objective and the eyepiece is observed to be 20 cm. The magnifying power of the telescope is 9. The focal lengths of the lenses are
a) 11 cm, 9 cm
b) 9 cm, 11 cm
c) 10 cm, 10 cm
d) 18 cm, 2 cm
Answer
1
Muhammad Arafath R Z
Subject: Physics
, asked on 18/4/18
Laws of motion Online 2018 mains
Q.21. A man in a car at location Q on a straight highway is moving with speed v. He decides to reach a point P in a field at a distance d from the highway (point M) as shown in the figure. Speed of the car in the field is half to that on the highway. What should be the distance RM, so that the time taken to reach P is minimum ?
1.
$\frac{d}{\sqrt{3}}$
2.
$\frac{d}{2}$
3. d
4.
$\frac{d}{\sqrt{2}}$
Answer
1
Muhammad Arafath R Z
Subject: Physics
, asked on 18/4/18
Laws of motion Online 2018 mains
Q.21. A man in a car at location Q on a straight highway is moving with speed v. He decides to reach a point P in a field at a distance d from the highway (point M) as shown in the figure. Speed of the car in the field is half to that on the highway. What should be the distance RM, so that the time taken to reach P is minimum ?
1.
$\frac{d}{\sqrt{3}}$
2.
$\frac{d}{2}$
3. d
4.
$\frac{d}{\sqrt{2}}$
Answer
1
Aparna Sahu
Subject: Physics
, asked on 18/4/18
Solve 26
Q26. A thin glass prism
$\left(\mathrm{\mu}=1.5\right)$
is immersed in water
$\left(\mathrm{\mu}=1.3\right)$
. If the angle of deviation in air for a particular ray be
$\mathrm{\delta}$
, then that in water will be
Answer
1
Aparna Sahu
Subject: Physics
, asked on 18/4/18
Solve qus no. 3:
3. A thin conave and thin convex lenses are in contact. The ratio of the magnitude of power of two lenses is 2/3 and focal length of combination is 30 cm, then the focal lengths of individual lenses are.
(a) 75 cm, 50 cm (b) -75 cm, 50 cm
(b) 75 cm, -50 cm (d) -15 cm, 10 cm
Answer
1
Aparna Sahu
Subject: Physics
, asked on 17/4/18
Solve this:
Solve qus no. 50
Q.50. A convex lens of focal length 30 cm forms an image of height 2 cm for an object situated at infinity. If a concave lens of focal length 20 cm is placed coaxially at a distance of 26 cm in front of convex lens, then size of final image would be
(a) 1.5 cm
(b) 2 cm
(c) 2.5 cm
(d) 4 cm
Answer
1
Aparna Sahu
Subject: Physics
, asked on 16/4/18
Solve qus no. 50
Q.50. A convex lens of focal length 30 cm forms an image of height 2 cm for an object situated at infinity. If a concave lens of focal length 20 cm is placed coaxially at a distance of 26 cm in front of convex lens, then size of final image would be
(a) 1.5 cm
(b) 2 cm
(c) 2.5 cm
(d) 4 cm
Answer
1
Vaishnavi
Subject: Physics
, asked on 15/4/18
A glass sphere (µ = 1.5) of radius 20 cm has a small air bubble 4 cm below its centre. The sphere is viewed from outside and along a vertical line through the bubble. The apparent depth of the bubble below the surface of sphere is (in cm)
(1) 13.33 (2) 26.67 (3) 15 (4) 30
Answer
1
Vaishnavi
Subject: Physics
, asked on 11/4/18
Solve this
34. The critical angle for refraction from glass air is 30
^{o }
and that from water to air is 37
^{o}
. Find the critical angle for refraction from glass to water .
1) sin
^{-1}
(5/6) 2) 51
^{o}
3'
3) 61
^{o}
2 4) 63
^{o}
3'
Answer
1
Vaishnavi
Subject: Physics
, asked on 11/4/18
$28.Therefractiveindexofdensermediumwithrespecttorerermediumis1.125.Thedifferencebetweenthevelocitiesoflightinthetwomediais0.25\times {10}^{8}m/s.\hspace{0.17em}Findthevelocitiesoflightinthetwomediaandtheirrefractiveindices.(c=3\times {10}^{8}m/s)$
Answer
1
Vaishnavi
Subject: Physics
, asked on 11/4/18
Solve this:
22. A monochromatic light passes through a glass
slab (
$\mu $
= 1.5) of thickness 9 cm in time t
_{1}
.If it takes
a time t
_{2}
_{ }
to travel the same distance through water
(
$\mu $
= -4/3). The value of (t
_{1}
-t
_{2}
) is
l) 5 x 10
^{-11 }
sec 2) 5 x 10
^{-8 }
sec
3) 2.5 x 10
^{-10 }
sec 4) 5 x 10
^{-10 }
sec
Answer
1
Aparna Sahu
Subject: Physics
, asked on 6/4/18
Solve this ..
Q.58. The focal lengths of the objective and the eyepiece of a microscope are 2 cm and 7 cm respectively. The separation between the lenses is 20 cm. At what distance from the objective should the object be placed to get the image at a distance of 25 cm from the eyepiece?
(a) 3.219 cm
(b) 2.319 cm
(c) 3.291 cm
(d) None of these
Answer
1
Aparna Sahu
Subject: Physics
, asked on 6/4/18
Solve this..
Q.54. A ray of light incident at an angle 45
$\xb0$
on an air-glass interface gets reflected. The angle of deviation of the ray is
(a) 45
$\xb0$
(b) 180
$\xb0$
(c) 135
$\xb0$
(d) None of these
Answer
2
Aparna Sahu
Subject: Physics
, asked on 6/4/18
Solve this.
Q57. One of the slit-width in Young's double -slit experiment is double the other. If the amplitude of the light wave is proportional to slit-width, then the ratio of the maximum and minimum intensity in the interference pattern is
(a) 3 : 1 (b) 6 : 1
(c) 9 : 1 (d) 12 : 1
Q58. The focal lengths of the objective and the eyepiece of a microscope are 2cm and 7cm respectively. The separation between the lenses is 20cm. At what distance from the objective should the object be placed to get the image at a distance of 25 cm from the eyepiece?
(a) 3.219 cm (b) 2.319 cm
(c) 3.291 cm (d) None of these
Answer
2
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36. When a small lamp is held 1.5 m above the surface of water in a tank, its image formed by reflection as the surface appears to coincide with image of the bottom of the tank ($\mu $ of water = 4/3). The depth of tank is

(a) 2 m

(b) 1.5 m

(c) 1 m

(d) 4 m

a) 11 cm, 9 cm

b) 9 cm, 11 cm

c) 10 cm, 10 cm

d) 18 cm, 2 cm

Q.21. A man in a car at location Q on a straight highway is moving with speed v. He decides to reach a point P in a field at a distance d from the highway (point M) as shown in the figure. Speed of the car in the field is half to that on the highway. What should be the distance RM, so that the time taken to reach P is minimum ?

1. $\frac{d}{\sqrt{3}}$

2. $\frac{d}{2}$

3. d

4. $\frac{d}{\sqrt{2}}$

Q.21. A man in a car at location Q on a straight highway is moving with speed v. He decides to reach a point P in a field at a distance d from the highway (point M) as shown in the figure. Speed of the car in the field is half to that on the highway. What should be the distance RM, so that the time taken to reach P is minimum ?

1. $\frac{d}{\sqrt{3}}$

2. $\frac{d}{2}$

3. d

4. $\frac{d}{\sqrt{2}}$

Q26. A thin glass prism $\left(\mathrm{\mu}=1.5\right)$ is immersed in water $\left(\mathrm{\mu}=1.3\right)$. If the angle of deviation in air for a particular ray be $\mathrm{\delta}$, then that in water will be

3. A thin conave and thin convex lenses are in contact. The ratio of the magnitude of power of two lenses is 2/3 and focal length of combination is 30 cm, then the focal lengths of individual lenses are.

(a) 75 cm, 50 cm (b) -75 cm, 50 cm

(b) 75 cm, -50 cm (d) -15 cm, 10 cm

Solve qus no. 50

Q.50. A convex lens of focal length 30 cm forms an image of height 2 cm for an object situated at infinity. If a concave lens of focal length 20 cm is placed coaxially at a distance of 26 cm in front of convex lens, then size of final image would be

(a) 1.5 cm

(b) 2 cm

(c) 2.5 cm

(d) 4 cm

Q.50. A convex lens of focal length 30 cm forms an image of height 2 cm for an object situated at infinity. If a concave lens of focal length 20 cm is placed coaxially at a distance of 26 cm in front of convex lens, then size of final image would be

(a) 1.5 cm

(b) 2 cm

(c) 2.5 cm

(d) 4 cm

(1) 13.33 (2) 26.67 (3) 15 (4) 30

34. The critical angle for refraction from glass air is 30

^{o }and that from water to air is 37^{o}. Find the critical angle for refraction from glass to water .1) sin

^{-1}(5/6) 2) 51^{o}3'3) 61

^{o}2 4) 63^{o}3'22. A monochromatic light passes through a glass

slab ($\mu $ = 1.5) of thickness 9 cm in time t

_{1}.If it takesa time t

_{2}_{ }to travel the same distance through water($\mu $ = -4/3). The value of (t

_{1}-t_{2}) isl) 5 x 10

^{-11 }sec 2) 5 x 10^{-8 }sec3) 2.5 x 10

^{-10 }sec 4) 5 x 10^{-10 }sec

Q.58. The focal lengths of the objective and the eyepiece of a microscope are 2 cm and 7 cm respectively. The separation between the lenses is 20 cm. At what distance from the objective should the object be placed to get the image at a distance of 25 cm from the eyepiece?

(a) 3.219 cm

(b) 2.319 cm

(c) 3.291 cm

(d) None of these

Q.54. A ray of light incident at an angle 45$\xb0$ on an air-glass interface gets reflected. The angle of deviation of the ray is

(a) 45$\xb0$

(b) 180$\xb0$

(c) 135$\xb0$

(d) None of these

Q57. One of the slit-width in Young's double -slit experiment is double the other. If the amplitude of the light wave is proportional to slit-width, then the ratio of the maximum and minimum intensity in the interference pattern is

(a) 3 : 1 (b) 6 : 1

(c) 9 : 1 (d) 12 : 1

Q58. The focal lengths of the objective and the eyepiece of a microscope are 2cm and 7cm respectively. The separation between the lenses is 20cm. At what distance from the objective should the object be placed to get the image at a distance of 25 cm from the eyepiece?

(a) 3.219 cm (b) 2.319 cm

(c) 3.291 cm (d) None of these