An electron is moving with velocity v in the direction of magnetic field B, then force acting on electron is
zero
e (v x B)
e (B x v)
200 J
Ten wires each of resistance 1 Ω are connected in parallel, then total resistance will be
10 Ω
1 Ω
0.1 Ω
0.001 Ω
Which of the following has same dimensions to that of Planck's constant?
Work
Energy
Linear momentum
Angular momentum
Half-life of radium is 1600 yr, then its 1/16th part will remain undecayed after
1200 yr
6400 yr
1800 yr
2200 yr
When a light beam enters into water from air, then which of the following does not change?
Velocity
Frequency
Wavelength
Amplitude
B.
Frequency
When light enter into another medium from one medium, then frequency does not change.
Atomic number of an atom is Z and mass number is m, then number of neutrons in its nucleus is
m − Z
m + Z
m × Z
In nth orbit of hydrogen atom energy , then energy required to displace electrons from n = 1 to n = 2 is
- 10.2 eV
3.4 eV
- 13.6 eV
1.51 eV