Answer:
a) 
b) 
Explanation:
From the question we are told that:
Wire Length 
Resistance 
Force 
Power 
a)
Generally the equation for Power is mathematically given by

Therefore



b)
Generally the equation for Magnetic Field is mathematically given by



Answer:
option (B)
Explanation:
Intensity of unpolarised light, I = 25 W/m^2
When it passes from first polarisr, the intensity of light becomes

Let the intensity of light as it passes from second polariser is I''.
According to the law of Malus

Where, θ be the angle between the axis first polariser and the second polariser.

I'' = 11.66 W/m^2
I'' = 11.7 W/m^2
Answer:
Hits per second=199 hit/s
Explanation:
#Given the angular velocity,
, radius of the record
and the distance between any two successive bumps on the groove as
.
The linear speed of the record in meters per second is:

#From
above, if the bumps are uniformly separated by 1m, then the rate at which they hit the stylus is:

Hence the bumps hit the stylus at around 199hit/s
Answer:
A few of the positive particles aimed at a gold foil seemed to bounce back
Explanation: