Simple Harmonic Motion — Physics STD 12 Science — Question

A copper wire has a square cross-section, 2.0 mm on a side.  It carries a current of 8 A and the density of free electrons is 8  . The drift speed of electrons is equal to

(a) 0.156 ×   m.s–1

(b) 0.156 ×   m.s–1

(c) 3.12 ×   m.s–1

(d) 3.12 ×   m.s–1

The direction of electric field created by a negative charge is ___________?

An electron is travelling along the x-direction. It encounters a magnetic field in the y-direction. Its subsequent motion will be

(a) Straight line along the x-direction	(b) A circle in the xz-plane
(c) A circle in the yz-plane	(d) A circle in the xy-plane

The electric potential at a point on the equatorial line of an electric dipole is:

64 drops of mercury each charged to a potential of 10V. They are combined to form one bigger drop. The potential of this drop will be (Assume all the drops to be spherical)

(a) 160 V

(b) 80 V

(c) 10 V

(d) 640 V

There is a current of 40 ampere in a wire of   area of cross-section.  If the number of free electron per   is ,  then the drift velocity will be     

(a) 1.25 ×   m/s

(b) 2.50 ×   m/s

(c) 25.0 ×   m/s

(d) 250 ×  m/s

A charged particle moves in a uniform magnetic field. The velocity of the particle at some instant makes an acute angle with the magnetic field. The path of the particle will be:

1. A straight line.
2. A circle.
3. A helix with uniform pitch.
4. A helix with nonuniform pitch.

Figure shows some equipotential lines distributed in space. A charged object is moved from point A to point B.

A double slit experiment is performed with light of wavelength 500 nm. A thin film of thickness 2 mm and refractive index 1.5 is introduced in the path of the upper beam. The location of the central maximum will

(a) Remain unshifted

(b) Shift downward by nearly two fringes

(c) Shift upward by nearly two fringes

(d) Shift downward by 10 fringes

Which of the following is conserved when light waves interfere

(a) Intensity

(b) Energy

(c) Amplitude

(d) Momentum