A magnetic field___________________?
(A) always exerts a force on a charged particle
(B) never exerts a force on a charged particles
(C) exerts a force if the charged particle is moving in the direction of the magnetic field lines
(D) exerts a force if the charged particle is moving perpendicular to the magnetic field lines
Two parallel wires carrying currents in the opposite directions____________________?
(A) repel each other
(B) attract each other
(C) have no effect upon each other
(D) they cancel out their individual magnetic fields
What is the value of the current in a wire of 10cm long at the right angle to a uniform magnetic field of 0.5 Weber/m2 when the force acting on the wire is 5N ?
(A) 1A
(B) 10A
(C) 100A
(D) 1000A
Magnetic force acting on a unit positive charge moving perpendicular to the magnetic field with a unit velocity is called____________________?
(A) magnetic flux
(B) magnetic field intensity
(C) magnetic induction
(D) self inductance
The net charge on n-type material is____________________?
(A) Positive
(B) Negative
(C) Both positive and negative
(D) Neutral
In a semiconductors the charge carriers are ___________________?
(A) Holes only
(B) Electrons only
(C) Electron and holes both
(D) All of the above
Holes can exist in____________________?
(A) Conductors
(B) Insulators
(C) Semi conductors
(D) All of the above
Many of the semi conductors are crystals of the type__________________?
(A) Face centred cubic
(B) Body centred cubic
(C) Simple cubic
(D) All of the above
A galvanometer basically is an instrument used to ____________________?
(A) detect current in a circuit
(B) measure current flowing through a circuit
(C) measure voltage across a circuit
(D) measure potential difference between two points in a circuit
Coil of a galvanometer is suspended in a radial magnetic field so that the deflecting torque on the coil is always___________________?
(A) BINA cosa
(B) BINA sina
(C) BINA tana
(D) BINA