Given :
An electron moving in the positive x direction experiences a magnetic force in the positive z direction.
To Find :
The direction of the magnetic field.
Solution :
We know, force is given by :
Here, q = -e.
Now, for above condition to satisfy :
So, 
Therefore, direction of magnetic field is negative y direction.
Hence, this is the required solution.
1. is D. Scientific method cannot be replaced.
2. is B.
3. is B as well.
I attached a picture of the diagram associated with this question.
Now,
When we check the vertical components of the tension in the rope, we will find that we have two equal components acting upwards.
These two components support the weight and each of them has a value of TcosΘ
The net force acting on the body is zero.
Fnet=Force of tension acting upwards-Force due to weight acting downwards
0 = 2TcosΘ -W
W = 2TcosΘ
T = W / 2cosΘ
Answer:
(B) The wavelength that a star radiates the most energy is inversely proportional to the temperature.
Explanation:
As we know that
According to Wien's law wavelength is inverse proportional to the temperature .
λ.T = Constant.
λ.∝ 1 /T
As we know that star radiates wavelength and this wavelength is inverse proportional to the temperature of the star.
The temperature of cool star is cooler than the temperature of hot star that is cool star looks red and hot star looks blue.Cool star have low energy and hot star have high energy.
So option B is correct.
(B) The wavelength that a star radiates the most energy is inversely proportional to the temperature.
