Sound interference is necessary to produce the phenomenon of
beats
doppler effect
acoustic resonance
echo
Correct answer is A
No explanation has been provided for this answer.
Which of the following is not a part of the electro-magnetic spectrum?
x-rays
microwaves
infrared radiation
alpha rays
Correct answer is D
No explanation has been provided for this answer.
Which of the following characteristics of light determines its colour?
velocity
wavelength
amplitude
intensity
Correct answer is B
No explanation has been provided for this answer.
2.5D
5.0D
10.0D
25.0D
Correct answer is C
\(\frac{1}{v} = \frac{1}{u}\)
m = \(\frac{v}{u} = \frac{1}{4} = \frac{v}{50}\)
v = 12.5
But \(\frac{1}{v} + \frac{i}{u} = \frac{1}{f}\)
= \(\frac{1}{50} + \frac{1}{12.5} = f\)
f = 10m
P = \(\frac{100}{10} = 10D\)
A concave mirror forms a magnified and errect image only when the object is placed
at the centre of curvature
at the focus
between the focus and the pole of the mirror
beyond the radius of curvature
Correct answer is C
No explanation has been provided for this answer.