A charged particle enters in a strong perpendicular magnetic field. Then its kinetic energy
increases
decreases
remains constant
None of these
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
D.
10
V = IR = xl
I × 10 = × 50 × 10-2 = 0.01
I = 0.01/10 = 10-3 = 10 mA
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