In an attempt to kill Batman , Joker devises another evil Plan.
He mounts a plane mirror AB on a turn table both of which are centered at O.
Around it he places a Death Laser on a ring shaped turn table which is concentric to the other turn table.
Both the tables can turn in either direction. Laser is fixed such that it always points at O.
He knows that to kill Batman he has to turn the ring turn table by 20 degrees more, in the anticlockwise direction, from the given situation in the picture. Fortunately the ring turning mechanism is jammed . So calculate the angle and the direction by which he has to turn the central turn table from the initial position in order to hit Batman.
In an attempt to kill Batman , Joker devises another evil Plan.
He mounts a plane mirror AB on a turn table both of which are centered at O.
Around it he places a Death Laser on a ring shaped turn table which is concentric to the other turn table.
Both the tables can turn in either direction. Laser is fixed such that it always points at O.
He knows that to kill Batman he has to turn the ring turn table by 20 degrees more, in the anticlockwise direction, from the given situation in the picture. Fortunately the ring turning mechanism is jammed . So calculate the angle and the direction by which he has to turn the central turn table from the initial position in order to hit Batman.
The correct option is C 10 degrees, clockwise
So, the ring table or we can say the incident ray needs to be rotated by 20 degrees in anticlockwise direction. As we know that, if the incident ray is rotated by θ, the reflected ray gets rotated by −θ.
So, to kill the batman, we understand that the reflected ray must be rotated by 20 degrees in clockwise direction.
Now, this has to be done by rotating the inner turntable or we can say the mirror.
Let's recall the relation between mirror rotation and reflected ray rotation.If the mirror is rotated by an angle θ,the reflected ray gets rotated by 2θ, i.e twice the magnitude and same sense of rotation.
So, how much we should rotate the table or the mirror ?
Since reflected ray has to be rotated by 20 degrees clockwise, the mirror should be rotated by 10 degrees clockwise.
So, the ring table or we can say the incident ray needs to be rotated by 20 degrees in anticlockwise direction. As we know that, if the incident ray is rotated by θ, the reflected ray gets rotated by −θ.
So, to kill the batman, we understand that the reflected ray must be rotated by 20 degrees in clockwise direction.
Now, this has to be done by rotating the inner turntable or we can say the mirror.
Let's recall the relation between mirror rotation and reflected ray rotation.If the mirror is rotated by an angle θ,the reflected ray gets rotated by 2θ, i.e twice the magnitude and same sense of rotation.
So, how much we should rotate the table or the mirror ?
Since reflected ray has to be rotated by 20 degrees clockwise, the mirror should be rotated by 10 degrees clockwise.
