## MSC Physics

# The center of mass of velocity is defined by

# A bob of mass m is moving in XY-plane as a simple pendulum. Its Lagrangian function is:

# The energy of an electron of de-Broglie wavelength 1Å in eV will be

**150.5**- 13.6
- 10.2
- 1.227

# The nature of bonding in diamonds is

- ionic
**covalent**- van der Waals
- metallic

# What is the length of a one-meter stick when it is moving at the speed of v = c / 2

**0.866 m**- 1.866 m
- 2.866 m
- 3.866 m

# The Compton wavelength of an electron (mc^{2} = 0.511 MeV) is of the order of

**10**^{-2 }Å- 1 Å
- 10 Å
- 10
^{2 }Å

# The energy gap in a semiconductor is

- Equal to insulator
**Less than an insulator**- More than an insulator
- None of these

# A lens of focal length 20 cm has a power of

- 0.20 diopters
**5 diopters**- 10 diopters
- 50 diopters

# A neutron enters in a magnetic field of strength B(Tesla) perpendicular to the magnetic lines of force, with speed v. The force on the neutron is

**Zero**- ∞
- evB
- ILB