Answer:
Magnetic field, 
Explanation:
Given that,
Velocity of electron, 
It enters a region of space where perpendicular electric and a magnetic fields are present.
Magnitude of electric field, 
We need to find the magnetic field will allow the electron to go through the region without being deflected.
Magnetic force on the electron,
.......(1)
Electric force on the electron, F = q E........(2)
From equation (1) and (2) we get:



B = 0.0002 T
or

Hence, this is the required solution.
Work = Force x Distance = 500 x 4 = 2000 Nm = 2000 J
vib. motion motion of wire of guitar
circular motion revolution of earth around sun
1ml 1cm3
1m3 100cm3
volume of liquid measuring cylinder
The Kepler's laws predict the planetary motion, so there are three laws for this, namely:
1. The orbit of a planet is an ellipse with the Sun (the sun is a star!) at one of the two focus.
2. A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time.
3. The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit.
So, let's use second law. The Sun sweeps out equal areas during equal intervals of time means that if A = B, the time the planet takes to travel A1A2 is equal to the time the planet takes to travel B1B2, but given that A = 2B, then takes twice the time to travel A1A2 compared to B1B2.
True
In fact, the weight of an object on the surface of the Earth is given by:

where m is the mass of the object and

is the gravitational acceleration on Earth's surface. If we use the mass of the object, m=3.0 kg, we find