Answer:
The radius of coil 2 = 2.7 cm
Explanation:
The number of coils = 2
It is given that both carry equal current and rotates in the magnetic field.
The given radius of coil 1 = 4.0 cm
Coil 1 rotates = 0.21 T field
Coil 2 rotates = 0.45 T filed.
The radius of coil 2 need to be calculated.
Torque action on dipole is given by
here T1 = T2

Answer:
The correct option is (b).
Explanation:
We need to find the work done to increase the speed of a 1 kg toy car by 5 m/s.
We know that, the work done is equal to the kinetic energy of an object i.e.

So, 12.5 J of work is done to increase the speed of a 1.0 kg toy car by 5.0 m/s.
The answer would be 2.63. Your welcome. This has been changed to the correct answer.
Answer:
Current, I = 2.3 A
Explanation:
We have,
Voltage of the battery in a circuit is 9 volts
Resistance of the circuit is 4 ohms
It is required to find the current in a circuit. When the voltage and the resistance of the circuit is given then we can find the current in it is given by Ohm's law as :

I is electric current

or
I = 2.3 A
So, the current in the circuit is 2.3 A.