ELECTRICITY & MAGNETISM
In a circuit Capacitor allows ________ current and blocks ___________ current
Alternating current & Direct current
Which Impurity is doped in Si to form N- type semi conductor?
a) Al b) B c) As d)none of the above
c) As
When the lines of action of two forces meet in one point then the forces are said to be _________ forces.
Concurrent forces
The waves in which material medium is required for their propagation are called as ___________
Mechanical waves
Amount of light entering into the eyes is controlled by________.
IRIS
A Negatively charged particle projected towards east is deflected towards north by Magnetic field.The field may be in which direction?
Upward Direction
The Energy band gap is maximum in
a) metals b) super conductors
c) insulators d) semi conductors
c) insulators
Units of moment of inertia of mass are :
Kg-m2
Kinetic theory of gases assumes that the collisions between are
a) perfectly elastic b) perfectly inelastic
c) may be elastic d) may be inelastic
a) perfectly elastic
Refractive index of four substances A,B,C,D are 1.31, 1.43, 1.33, 2,4 respectively.The speed of light is maximum in __________.
A
In an Oscillating LC circit the maximun charge on the capacitor is 'Q' . The charge on the capacitor when energy is stored equally between the electric and magnetic fields is _______
Q/√2
The part of a transistor which is most heavily doped to produce large number of majority carriers is
a) emitter b) base c)collector
d) can be any of the above three
a) emitter
The Point through which the whole weight of the body acts, irrespective of its position is known as
Centre of gravity
Specific heat of air at constant pressure is equal to
a) 1 b) 0.24 c) 2.4 d) 0.024
b) 0.24
A Convex lens forms a real,diminished point sized image at focus ,then the position of object is at ________
Infinity
Two coils are placed close to each other .The mutual inductance of the pair of coils depends on ?
Position & Orientation of the coils
By increasing the temperature , the specific resistance of a conductor and a semi conductor
a) increases for both b) decreases for both
c) increases, decreases d) decreases, increases
c) increases, decreases
The motion in which an object moves in bilaterely symmetrical, parabolic path is called _________.
projectile
A carnot engine can works between 600k and 300k . The efficiency of the engine is ____%
50%
Soap bubble appears coloured due to phenomenon of_________
Interference
A vertical rod of length 'l' is moved with constant velocity 'v' towards East. The vertical component of the Earth's magnetic field is 'B' and the angle of dip is 'θ '. The induced emf in the rod is _____
Blv cotθ
At absolute zero, Si acts as
a) non-metal b) metal c) insulator d) none
c) insulator
Co-efficient of Restitution(COR) for perfectly elastic bodies is _____.
1
Which of the following frequencies will be suitable ford beyond- the - horizon communication using sky waves?
a) 10 kHz b) 10MHz c) 1GHz d) 1000GHz
b) 10MHz
When a ray of light enters from one medium to another , then which of the following does not change
1. Frequency 2. Wave length 3. Speed 4. Amplitude
Frequency