The period of a 10 kHz radio wave traveling at 10\(^{8}\) ms\(^{-1}\) is--
3.0 x 10\(^{-5}\)s
1.0 x 10\(^{-4}\) s
1.0 x 10\(^{4}\)s
3.0 x 10\(^{4}\)s
Correct answer is B
The relation between period and frequency is that one is the inverse of the other.
By definition:
Frequency = 1/period.
or
period = 1/frequency → 1/ 10,000
period = 0.0001 or 1.0 x 10\(^{-4}\) s
move in a circle
repel each other
remain stationary
attract each other
Correct answer is D
Two conductors with current flowing in the same direction will attract.
make the deflection of the needle proportional to the current
increase the sensitivity of the galvanometer
decrease the magnetic flux produced by the magnet
make the permanent magnet stronger
Correct answer is B
Sensitivity of a galvanometer increases when number of turns, area of coil and magnetic field increase
The power of the lens is +2.5D. What is the radius of the curvature?
2.5 cm
25.0 cm
40.0 cm
80.0 cm
Correct answer is D
The power of a lens is defined as the reciprocal of its focal length in metres:
P = \(\frac{100}{f}\) → 2.5 = \(\frac{100}{f}\)
where P is the power in diopters and f is the focal length in metres.
2.5 * f = 100
f = \(\frac{100}{2.5}\)
f = 40
Where f = \(\frac{r}{2}\)
radius of the curvature[r] = f * 2 → 40 * 2
r = 80cm
doppler effect
beat
interference
resonance
Correct answer is B
beat, in physics, the pulsation caused by the combination of two waves of slightly different frequencies