A charged particle enters in a strong perpendicular magnetic field. Then its kinetic energy
increases
decreases
remains constant
None of these
C.
remains constant
The magnetic field is always perpendicular to its velocity. So, it does not affect the kinetic energy.
Calculate the current which will produce a deflection of 30° in a tangent galvanometer, if its reduction factor is 3 A.
1.732 A
0.732 A
3.732 A
2.732 A
The inductance of a coil in which a current of 0.2 A is increasing at the rate of 0.5 A/s represents a power flow of 0.5 W, is
2 H
5 H
10 H
20 H
The mutual inductance of an induction coil is 5 H. In the primary coil, the current reduces from 5 A to zero is s What is the induced emf in the secondary coil?
2500 V
25000 V
2510 V
Zero
Relative permeability of iron is 5500, then its magnetic susceptibility will be
5500 × 107
5500 × 10-7
5501
5499
What is shape of· magnet in moving coil galvanometer to make the radial magnetic field?
Concave
Horseshoe magnet
Convex
None of the above
A cyclotron can accelerate
β-particles
α-particles
high-velocity gamma rays
high-velocity X-rays
A potentiometer having the potential gradient of 2 mV/cm is used to measure the difference of potential across a resistance of 10Ω. If a length of 50 cm of the potentiometer wire is required to get the null points the current passing through the 10Ω resistor is (in mA)
1
2
5
10
Maximum energy is evolved during which of the following transitions?
n = 1 to n= 2
n = 2 to n= 6
n = 2 to n= 1
n = 6 to n= 2