When plate voltage in diode valve is increased from 100V to 150V. Then, plate increases from 7.5 mA to 12 mA, then dynamic plate resistance will be
10 kΩ
11 kΩ
15 kΩ
11.1 kΩ
A charged particle is accelerated by a potential of 200 V. If its velocity is 8.4 × 108 m/s, then value of e/m for that particle is
17.6 × 1016
14.5 × 1012
1.76 × 1015
1.45 × 1015
Two capacitors of capacities C1 and C2 are charged upto the potential V1 and V2 then condition for not flowing the charge between on connected them in parallel is
C1 = C2
C1V1 = C2V2
V1 =V2
If we change the value of R, then
voltage does not change on L
voltage does not change on LC combination
voltage does not change on C
voltage changes on LC combination
Electric field at point 20 cm away from the centre of dielectric sphere is 100 V/m, radius of sphere is 10 cm, then the value of electric field at a distance 3 cm from the centre is
100 V/m
125 V/m
120 V/m
0
Real power consumption in a circuit is least when it contains.
high R, low L
high R, high L
low R, high L
high R, low C
Magnetic field of the earth is H =0.3 g. A magnet is vibrating 5 oscillations per min then the dippreciation required in the magnetic field of the earth of increase time period upto 10 oscillations per minute is
2.25 g
0.6 g
0.9 g
0.12 g
A.
2.25 g
The dipole in a uniform magnetic field
T =
Where I is the moment of inertia
H is the magnetic field
We know that
T
∴
⇒
∴ H2 = 0.75
Dippreciation in field
= 3 - 0.75
= 2.25 g