Physics
Out of the following, which statement is incorrect ?
- The lamination of core prevents loss of energy due to eddy currents.
- The core is made of soft iron.
- A transformer can be used with d.c.
- A closed core is used so as to provide a closed path for magnetic field lines.
Related Questions
In a step up transformer:
- Ns = Np
- Ns < Np
- Ns > Np
- nothing can be said
A step up transformer …………… the current whereas a step down transformer …………… the current.
- increases, increases
- decreases, decreases
- decreases, increases
- increases, decreases
Assertion (A): A current carrying solenoid when suspended freely sets itself in the north-south direction just like a bar magnet.
Reason (R): The end of the solenoid where the direction of current is anti-clockwise behaves as a north pole and the end where the direction of the current is clockwise behaves as a south pole.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true and R is not the correct explanation of A.
- assertion is false but reason is true.
- assertion is true but reason is false.
Assertion (A): The strength of the magnetic field produced due to a current carrying circular coil increases with an increase in the strength of the current.
Reason (R): Magnetic field strength is inversely proportional to the current flowing in a coil.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true and R is not the correct explanation of A.
- assertion is false but reason is true.
- assertion is true but reason is false.