Practice Physics set 6 - general science mcq Online Quiz (set-1) For All Competitive Exams
Q-1) What temperature is the same on celsius scale as well as on Fahrenheit scale?
(a)
(b)
(c)
(d)
$C/5 = {F - 32}/9$ Here C = F
$C/5 = {F - 32}/9$ ⇒ 9C = 5C – 160
4C = – 160 ⇒ C = – 40°C.
Thus at –40°C and –40° F the temperture is same.
Q-2) Consider the following three statements- Heating 1 kg of water from 10°C to 50°C
- Melting 600 g of ice at 0°C
- Converting 300 g of ice at 0°C to water at 50°C
Which one of the following shows the correct arrangement of the quantity of heat required in the above process in increasing order of magnitude? Choose the correct answer from the codes give below
(a)
(b)
(c)
(d)
Q-3) How much should minimum distance be between the source of sound and reflecting surface, so that an echo can be heard clearly?
(a)
(b)
(c)
(d)
Q-4) A shrill sound has a ______ pitch and a dull sound has a _____ pitch.
(a)
(b)
(c)
(d)
Q-5) On adding common salt to water, the boiling point and freezing point of water will
(a)
(b)
(c)
(d)
Q-6) Which of the following processes result in cooling ?
- Evaporation of liquid
- Compression of gas
- Shaking a liquid in a vessel
- Adiabatic expansion of a gas
Select the correct answer using the code given below :
(a)
(b)
(c)
(d)
- The process of a liquid changing into its vapour below its boiling point is called evaporation. In this process remaining water after evaporation loses heat and gets cooled.
- If a gas is compressed, work is done on it which results in heating of the system or an increase in temperature.
- On shaking a liquid in a vessel, the kinetic energy of liquid molecules increases and hence, the temperature of the system increases.
-
In adiabatic process ΔQ = 0
From the first law of thermodynamics,
ΔQ = ΔU + ΔW
We have ΔU + ΔW = 0
If the gas expands adiabatically (DW→positive), DU will be negative, so internal energy and hence, the temperature of the system will decrease. Thus, the gas is cooled.
Thus option (b) is correct.
Q-7) Consider the following statements :
- The shock waves produced by a supersonic aircraft do not have much intensity.
- The speed of sound is maximum in solids.
- A bat emits ultrasonic waves.
- Sound waves of frequency below audible range are termed as ultrasonic.
Which of the statements given above is/ are correct?
(a)
(b)
(c)
(d)
A shock wave is a type of propagating disturbance. Like an ordinary wave, it carries energy and can propagate through a medium (solid, liquid, gas or plasma) or in some cases in the absence of a material medium. Across a shock wave there is always an extremely rapid rise in pressure, temperature and density of the flow.
Ultrasound is sound with a frequency greater than the upper limit of human hearing (greater than 20 kHz).
Q-8) FM broadcasting service uses the range of frequency bands between
(a)
(b)
(c)
(d)
Q-9) Optical fibre works on the principle of
(a)
(b)
(c)
(d)
Q-10) Consider the following statements: - Principle of superposition can be used for any physical quantity.
- Principle of superposition can be used only when amplitude of quantity is small.
- It is not possible to have interference between the waves produced by two independent sources of same frequency.
- For interference of two waves the phase difference between the waves remain constant.
Which of the statements given above are correct?
(a)
(b)
(c)
(d)
Principle of superposition is applicable in wave motion.