In amplitude modulation, the amplitude of the carrier wave is 10 V and the amplitude of one of the side bands is 2 V. The modulation index is:
The voltage gain and current gain of a transistor amplifier in common emitter configuration are respectively 150 and 50. If the resistance in the base circuit is 850 Ω\OmegaΩ, then the resistance in the collector circuit is:
One mole of radium has an activity of 16.3×1037 \frac{1}{6.3 \times 10^{37}} 6.3×10371 kilo curie. Its decay constant is:
The speed of the electron in a hydrogen atom in the n=3 n = 3 n=3 level is:
An inductor and a resistor are connected in series to an AC source of voltage 144sin(100πt+π2) 144\sin(100\pi t + \frac{\pi}{2}) 144sin(100πt+2π) volts. If the current in the circuit is 6sin(100πt+π2) 6\sin(100\pi t + \frac{\pi}{2}) 6sin(100πt+2π) amperes, then the resistance of the resistor is:
The ratio of the number of turns per unit length of two solenoids A and B is 1:31:31:3 and the lengths of A and B are in the ratio 1:21:21:2. If the two solenoids have the same cross-sectional area, the ratio of the self-inductances of the solenoids A and B is:
At a place where the magnitude of the earth's magnetic field is 4×10−5 T4 \times 10^{-5} \, T4×10−5T, a short bar magnet is placed with its axis perpendicular to the earth's magnetic field direction. If the resultant magnetic field at a point at a distance of 40 cm from the center of the magnet on the normal bisector of the magnet is inclined at 45∘45^\circ45∘ with the earth's field, the magnetic moment of the magnet is:
Two concentric thin circular rings of radii 50 cm and 40 cm each, carry a current of 3.5 A in opposite directions. If the two rings are coplanar, the net magnetic field due to the two rings at their centre is:
Two long straight parallel conductors A and B carrying currents 4.5 A and 8 A respectively are separated by 25 cm in air. The resultant magnetic field at a point which is a distance of 15 cm from conductor A and 20 cm from conductor B is:
In the given circuit, if the potential at point B is 24 V, the potential at point A is:
Three point charges +q,+2q, +q, +2q, +q,+2q, and +4q +4q +4q are placed along a straight line such that the charge +2q +2q +2q lies equidistant from the other two charges. The ratio of the net electrostatic force on charges +q +q +q and +4q +4q +4q is: