Questions

The weight of the man mg is acting on the floor. As the lift is moving up with an acceleration, say a, the man too in it is having this acceleration. The force producing this acceleration is ma. By Newton's third law, this force will have an equal reaction pressing the floor equal to ma. Therefore the total resultant reaction on the floor is mg+ma = m(g+a) which is mg, the weight of the man. So (a) is correct.

World hemophilia day is observed globally on 17 April.

Here Joystick, Mouse and Scanner are Input devices through which data is given to the computers. But Headphones are output devices through which sound comes as an output from the computer or any devices.