electromagnet
When a electric current is passed through an insulated wire that is coiled around an iron core, like a nail, an electromagnet is created.
The Answer is Option C
I think...
Sorry If i am wrong...
Answer:
<h2>
E = 2.8028*10⁻¹⁹ Joules</h2>
Explanation:
The minimum energy needed to eject electrons from a metal with a threshold frequency fo is expressed as E = hfo
h = planck's constant
fo = threshold frequency
Given the threshold frequency fo = 4.23×10¹⁴ s⁻¹
h = 6.626× 10⁻³⁴ m² kg / s
Substituting this value into the formula to get the energy E
E = 4.23×10¹⁴ * 6.626 × 10⁻³⁴
E = 28.028*10¹⁴⁻³⁴
E = 28.028*10⁻²⁰
E = 2.8028*10⁻¹⁹ Joules
Answer:
a) Beth will reach before Alan
b)Beth has to wait 20 min for Alan to arrive
Explanation:
let 'd' be distance b/w Los Angeles and San Francisco i.e 400 mi
considering ,
Alan's speed
=50mph
Beth's speed
=60mph
->For Alan:
The time required
= d/
= 400/50 => 8h
-> For beth:
The time required
=> 6h 40m
Alan will reach at 8:00 a.m +8h = 4:00p.m.
Beth will reach at 9:00 a.m +6h 40m= 3:40p.m.
a) Beth will reach before Alan
b)Beth has to wait 20 min for Alan to arrive
Answer:

Explanation:
Given:
Thickness of the paperweight cube, 
apparent depth from one side of the inbuilt paper in the plastic cube, 
apparent depth from the other side of the inbuilt paper in the plastic cube, 
Now as we know that refractive index is given as:

- Let the real depth form first side of the slab be,

- Then the depth from the second side of the slab will be,

Since refractive index for an amorphous solid is an isotropic quantity so it remains same in all the direction for this plastic.




Now the refractive index:


