Physics Questions and Answers
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
Which of the following statements about waves in pipes is correct?
for open pipes, there is only one end correction to be accounted for
for closed pipes, there are two end corrections to be accounted for
only odd harmonics are possible in closed pipes
all harmonics are possible in closed pipes
Correct answer is C
No explanation has been provided for this answer.
14Hz
18Hz
28Hz
56Hz
Correct answer is C
The formula for the frequency in a stringed instrument : \(f = \frac{1}{2} \sqrt{\frac{T}{m}}\)
f = frequency; T = tension in the string; m = mass per unit lenth of the string.
f\(_1\) = 14 = \(\frac{1}{2} \sqrt{\frac{T}{m}}\).
When T is quadrupled, we have
f\(_2\) = new frequency = \(\frac{1}{2} \sqrt{\frac{4T}{m}}\)
= 2(\(\frac{1}{2} \sqrt{\frac{T}{m}}\))
= 2 f\(_1\)
= 2 x 14
= 28 Hz
Which of the following radiations has it's frequency lower than that of infrared radiation?
Ultra-violet rays
gamma rays
x-rays
radio waves
Correct answer is D
No explanation has been provided for this answer.
Which of the following statements about the Galilean telescope is not correct?
the final image is inverted
it is shorter than terrestrial telescope
the final image is erect
it has a small field of view
Correct answer is A
No explanation has been provided for this answer.
10cm
12cm
50cm
60cm
Correct answer is B
Lens formula:
\(\frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i}\)
where f, d\(_o\) and d\(_i\) are the focal length, object distance and image distance respectively.
The distance from the lens to the focal point is called the focal length. For converging lenses, the focal length is always positive, while diverging lenses always have negative focal lengths.
⇒ \(\frac{-1}{30} = \frac{1}{d_o} + \frac{1}{20}\)
\(\frac{1}{d_o} = \frac{-1}{30} - \frac{1}{20}\)
\(\frac{1}{d_o} = \frac{-2 + -3}{60}\)
→ \frac{-5}{60}\) = \frac{-1}{12}\)
\(d_o = - 12 cm\)
The object distance -12cm = 12cm on the other side of the lens.