Physics Class 10th

281. The turn ratio of a transformer is 10. It means:

A) IS= 10IP

B) NS = NP I 10

C) NS = 10NP

D) VS = VP / 10

282. The transformer has NP = 100 and NS = 500, if 6 volt DC is applied across primary the induced voltage is:

A) 0 V

B) 30 V

C) 15 V

D)  60 V

283. Iron core is used in transformer to:

A) Enhance the flux

B) Decrease the flux

C) Keep the flux same

D) Both A and B

284. Transformers work on the Principle of:

A) Self Induction

B) Mutual Induction

C) Electrostatics

D) Induction

285. Equation for transformer is

A) NS / V= VS / NS

B) NS / NP = VP / VS

C) VS/VP = NS / NP

D) VP / NP = NS /NP

286. The number of lines of force in a magnetic field depends upon:

A) Shape of Coil

B) Size of Coil

C) Magnet

D) Strength of Field

287. If current is flowing from bottom end to the top end in a wire, according to right hand rule the direction of line force will be:

A) Anti clock wise

B) Clock wise

C) Left to right

D) Along the conductor

288. The End of the solenoid from which the lines of force emerge out is called:

A) North Pole

B) South Pole

C) North and South Pole

D) none

289. The End of the Solenoid from which lines of force enter is called:

A) North Pole

B) South Pole

C) North and South Poles

D) None

290. The magnetic field of the solenoid resembles:

A) Iron Wire

B) U shape magnet

C) Bar Magnet

D) Point charge

291. A current carrying conductor produces a field around it is called:

A) Elecrtric Field

B) Magnetic Field

C) Both A and B

D) None

292. According to Fleming’s Left hand rule the direction of the magnetic field is indicated by:

A) Thumb

B) Forefinger

C) Middle Finger

D) Right hand Rule

293. According to Fleming left hand rule the direction of the force on the conductor is given by:

A) Thumb

B) Fore Finger

C) Middle Finger

D) None

294. The force on a current carrying conductor is maximum If the angle between the field and conductor is:

A) 0⁰

B) 90⁰

C) 180⁰

D) 45⁰

295. The force on the current carrying conductor is minimum if the angle between conductor and field is:

A) 0⁰

B) 70⁰

C) 45⁰


296. The DC motor split rings are made up of:

A) Steel

B) Carbon

C) Copper

D) Iron

297. Who discovered electromagnetic induction?

A) Michael Faraday

B) Fleming

C) Ohm

D) Coulomb

298. When did Faraday discover Electromagnetism?

A) 1841

B) 1831

C) 1821

D) 1811

299. Which type of energy is converted into mechanical energy in DC Motor?

A) Magnetic

B) Heat

C) Electrical

D) Chemical

300. Which device has two coil, primary and secondary?

A) DC Motor

B) Transformer

C) AC Generator

D) A and B