Answer: 2 cm
Explanation:
Given , for a converging lens
Focal length : 
Height of object : 
Object distabce from lens : 
Using lens formula:
, we get
, where v = image distance from the lens.
On solving aboive equation , we get

Formula of Magnification :
, where h' is the height of image.
Put value of u, v and h in it , we get

Hence, the height of the image is 2 cm.
Answer:
yes it doesn't matter
Explanation:
it doesn't matter because troughs and crests are the same and either can be used
Answer:a. Magnetic dipole moment is 0.3412Am²
b. Torque is zero(0)N.m
Explanation: The magnetic dipole moment U is given as the product of the number of turns n times the current I times the area A
That is,
U = n*I*A
But Area A is given as pi*radius² since it is a circular coil
Radius given is 5cm converting to meter we divide by 100 so we have our radius to be 0.05m. So area A is
A = 3.142*(0.05)² =7.86*EXP {-3} m²
Current I is 2 A
Number of turns is 20
So magnetic dipole moment U is
U = 20*2*7.86*EXP {-3}=0.3142A.m²
b. Torque is given as the cross product of the magnetic field B and magnetic dipole moment U
Torque = B x U =B*U*Sine(theta)
But since the magnetic field is directed parallel to the plane of the coil from the question, it means that the angle between them is zero and sine zero is equals 0(zero) if you substitute that into the formula for torque you will find out that your torque would equals zero(0)N.m
Answer:

Explanation:
We are given that
Current in wire=40 A
Magnetic field=
T( vertically downward)
We have to find the resultant magnitude of the magnetic field 29 cm above the wire and 29 cm below the wire.
According to Bio-Savart law, the magnetic field exerted by the wire at distance R is given by

We have R=29 cm=
1 m=100 cm
Substitute the values in the given formula

The resultant magnetic field is given by

Substitute the values then we get


The resultant magnitude of magnetic field is same above and below the wire as it is at same distance.
The resultant magnitude of the magnetic field 29 cm below the wire=
Hence, the resultant magnitude of the magnetic field 29 cm above the wire=
<em>The answer is </em>Ninth <em>and </em>Tenth <em>grade so the answer would be</em> B
<em>I hope this helps you </em>