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 / VP = VS / NS
B) NS / NP = VP / VS
C) VS/VP = NS / NP
D) VP / NP = NS /NP
A
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
D)60⁰
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