Answer:
He should stand from the center of laser pointed on the wall at 1.3 m.
Explanation:
Given that,
Wave length = 650 nm
Distance =10 m
Double slit separation d = 5 μm
We need to find the position of fringe
Using formula of distance



Put the value into the formula


Hence, He should stand from the center of laser pointed on the wall at 1.3 m.
When red light illuminates a grating with 7000 lines per centimeter, its second maximum is at 62.4°. What is the wavelength of this light?
ans: 633nm
Pressure increases with increasing depth. h2=2hh
Explanation:
The magnetic force acting on a current carrying wire in a uniform magnetic field is given by :

or

Where
is the angle between length and the magnetic field
The magnetic force is perpendicular to both current and magnetic field. It is maximum when it is perpendicular to both current and magnetic field.
So, the correct options are :
- The magnetic force on the current-carrying wire is strongest when the current is perpendicular to the magnetic field lines.
- .The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the field.
- The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the current.