386. When a charge is given to a conductor
A. it distributes uniformly all over the surface
B. it distributes uniformly all over the volume
C. it distributes on the surface, inversely proportional to the radius of curvature
D. it stays where it was placed

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387. Inside a hollow conducting sphere
A. electric field is zero
B. electric field is an non-zero constant
C. electric field changes with the magnitude of the change given to the conductor
D. electric field changes with distance from the centre of the sphere

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388. Which material is used in controlling chain reaction in a nuclear reactor?
A. Thorium
B. Heavy water
C. Boron
D. Beryllium

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389. A circuit with a resistor, inductor and capacitor in series is resonant of fo Hz. If all the component values are now doubled, the new resonant frequency is
A. 2f0
B. still f
C. f0/4
D. f012

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390.  If the length of a wire of resistance R is uniformly stretched to n times its original value, its new resistance is
A. nR
B.(c) n2R
C.(b) R/n
D. R/n2

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391.  When the plate area of a parallel plate capacitor is increased keeping the capacitor voltage constant, the force between the plates.
A. increase
B. decreses
C. remains constant
D. may increase or decrease depending on the metal making up the plates.

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392. An electron with velocity u is placed in an electric field E and magnetic field B. The force experienced by the electron is given by
A. ?eE
B.?eu x B
C. ?e(u x E + B)
D. ?e(E +11 x B)

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