00:01
Hello students, here is a given question and the question says an object is placed in front of a conchew mirror.
00:07
Here is a concave mirror is given and the focal length for this, the focal length for this is negative, will be negative, that is 20 centimetre is given.
00:19
The image form is three times of the size of the object.
00:23
Then the magnetification is equal to the three.
00:26
Calculate the two possible distance of the object from the mirror okay are two possible possible distance distance of object okay we have to find first of all in the conchon conchial mirror okay in the conchial mirror this is the first situation okay this is the first situation when this is p this is c and this is a okay when the magnification is equal to 3, when the object is placed here, this is the object, then the image will be here at the 3 type.
01:08
This will be the real image.
01:10
Here the real image.
01:13
And now, for the second case, this will be our mirror and here, this is the p, this is and this is become c.
01:24
That means if the object is placed here, then image will be here.
01:28
Okay, this is a three times, okay, and this is the virtual image, virtual image, okay? this is the two positions, okay? then now, now we know that when this will become happen is the real image, then the magnification will be negative.
01:48
This is the minus of three, okay, and when this is then the magnification is equal to the plus three, okay? now, we have to find out this.
01:57
Tocal length is given, that is minus 20 cents.
01:59
Then now we know that, we know that, okay? what is this? this is the magnification is equal to this is h -i by h -0.
02:13
Means the height of the image divided by height of the object is equal to minus v by u.
02:19
Okay? then this will become minus of 3 is equal to minus of v by u...