\(\frac{1}{2}\)
\(\frac{8}{9}\)
\(\frac{9}{8}\)
\(\frac{17}{12}\)
2
Correct answer is C
Ray travelling from water to glass;
\(\frac{\text{speed of light in air}}{\text{speed of light in glass}}\) = \(\frac{3}{2}\)
= 3 x 108ms-1
X = 2 x 108ms-1
\(\frac{\text{speed of light in air}}{\text{speed of light in water}}\) = \(\frac{4}{3}\)
= \(\frac{3 \times 10^8}{g}\)
Y = 2.25 x 108ms-1
from water to glass;
Refractive = \(\frac{\text{speed of light in water}}{\text{speed of light in glass}}\)
= \(\frac{2.25 \times 10^8}{2.00 \times 10^8}\)
= 1.125
= \(\frac{9}{8}\)
the car will be able to stop immediately the driver notices the dog
the car will stop 30m after hitting the dog
the car will stop 20m in front of the dog
the driver will quickly reverse the car
the car will stop 5m beyond the dog
Correct answer is B
F=ma
2000=800 x a
a = \(\frac{2000}{800}\) → 2.5
V\(^2\)=u\(^2\)+2as
400=2 × 2.5 × S
S =400 ÷ 5 → 80
: 80 - 50 = 30
The car will stop 30m after hitting the dog
All of the following frequencies are overtones of 320 Hz EXCEPT
960Hz
640Hz
520Hz
1280Hz
1600Hz
Correct answer is C
Overtones are frequency which are multiples of fundamental frequency
Fundamental frequency - f1 = 320Hz
Overtones 320 x 2 = 640Hz
320 x 3 = 960HZ
320 x 4 = 1280Hz
320 X 5 = 1600hZ
567km
410km
594km
500km
600km
Correct answer is D
R2 = 3002 + 4002
R2 = 90000 + 160000
R = \(\sqrt{250000}\)
= 500km
The resistance of a 240V, 60 watt electric filament bulb is
0.25\(\Omega\)
480\(\Omega\)
60\(\Omega\)
240\(\Omega\)
960\(\Omega\)
Correct answer is E
power = IV
power = \(\frac{V^2}{R}\) = 60
= \(\frac{240^2}{R}\)
= 960\(\Omega\)