Q. A man standing in front of a wall produces a sound and hears an echo after 3s. He walks 'x' m away from the wall and produces the same sound. Now he hears an echo after 5.25s. Calculate the distance he walked away from the wall. (Speed of sound in air is 340 m/s)
Q. What is an electrical fuse? State two characteristics of an electrical fuse.
Q. What is internal resistance of a cell? Write two factors on which it depends.
Q. In the circuit diagram given below, a cell of 9V and internal resistance 0.5 ohm is connected across a resistor A of 2 ohm in series and two resistors 2 ohm and 6 ohm which are in parallel.
Dear Student
Neither of your question parts are full. So i am giving answer of few questions
(ii)
The power of a convex lens is positive as a convex lens has a positive focal length, while the power of a concave lens is negative as concave lens has a negative focal length.
So negative sign mean child is using concave lens so he has myopia or near sightedness.
(iii) F = 1/P = -1/2.5 =- 0.4 m = - 40 cm
Please post different questions in different threads.
Regards
Neither of your question parts are full. So i am giving answer of few questions
(ii)
The power of a convex lens is positive as a convex lens has a positive focal length, while the power of a concave lens is negative as concave lens has a negative focal length.
So negative sign mean child is using concave lens so he has myopia or near sightedness.
(iii) F = 1/P = -1/2.5 =- 0.4 m = - 40 cm
Please post different questions in different threads.
Regards