IMPORTANT PHYSICS QUESTIONS FOR NDA EXAM
Every year almost 20-25 questions from various topics of physics were asked in NDA & NA exam hence, Physics is considered as a very important section of GAT i.e. General ability Test paper of National defence academy & naval academy examination. Since the syllabus is quite vast it is important to practice regularly some question of physics to cover and revise it completely on time. So, for those candidates preparing for NDA 2 2019 exam, here we are providing some questions of physics based on previous year paper of NDA to understand the basic pattern and type of questions of the examination. Try to practice these questions and understand the concept behind it.
QUESTIONS WITH SOLUTION
Q.1 Concave mirror is used in headlights of vehicles, because it
(a) Focuses light from the bulb onto nearby vehicles
(b) Sends parallel rays
(c) Fits well into the shape of the headlight
(d) is cheaper than other mirrors
Sol. (b) When object is kept at the focus of a concave mirror, the light rays after reflection from its travels parallel to each other .Therefore, the bulb of the headlight are kept and the focus of the concave mirror , thereby spreading out the light after reflection.
Q.2 If some object is weighed when submerged in water, what will happen to its weight compared to its weight in air?
(a) Increase
(b) Decrease
(c) Remain exactly the same
(d) Increase or decrease cannot be predicted.
Sol. (b) Weight of object will decrease as compared to its weight in air this is explain by Archimedes principle according to this if an object is immersed in a fluid it experiences an Apparent loss of weight which is equal to the weight of fluid displaced.
Q.3 An optical illusion which occurs mainly in deserts during hot summer is based on the principle of
(a) Reflection
(b) Interference
(c) Dispersion
(d) Total Internal Reflection
Sol. (d) An optical illusion in desert is based on the phenomenon of Total Internal Reflection (TIR) of light. It is the phenomenon in which when light rays is incident on a refracting medium at an angle greater than the critical angle whole of the light is reflected back to the same medium therefore when the layers of air close to the ground have wearing temperature with hottest layer near the ground light from a distance tree may undergo total internal reflection and the Apparent image of the tree may create an illusion to the observer.
Q.4 The amount of heat required to change a liquid to gaseous state without any change in temperature is known as
(a) Specific heat capacity
(b) Mechanical equivalent of heat
(c) Latent heat of vaporisation
(d) Quenching
Sol. (c) The amount of heat required to change a liquid to gaseous state without any change in temperature is known as latent heat of vaporization
Q.5 Which one of the following statements is not correct ?
(a) The longest wavelength of light visible to human eye is about 700nm
(b) The shortest wavelength of light visible to human eye is about 400nm
(c) The wavelength of Gamma Rays is longer than that of X-rays
(d) The ability of a telescope to form separable image of closed object is called its resolving power
Sol. (c)Visible light has wavelengths roughly in the range of 382nm to 780nm. The gama ray region and the X-ray region overlap considerably. On the average, wavelength of Gamma Rays are shorter than that of X-rays. The wavelengths of X-rays are about 10-8 m and of gamma rays 10-10 m .
Q.6 A particle is executing simple harmonic motion which one of the following statements about the acceleration of the oscillating particle is true ?
(a) It is always in the opposite directions to velocity
(b) It is proportional to the frequency of oscillation
(c) It is minimum when the speed is maximum
(d) It decreases as the potential energy increases
Sol. (c) In simple harmonic motion(SHM) a particle moves to and fro repeatedly on a straight or nearby straight path about a mean position.
Q.7 Simple circuit contains a 12V battery and bulb having 24 ohm resistance when turn on the switch diameter connected to the circuit would read
(a) 0.5 A
(b) 2 A
(c) 4 A
(d) 5 A
Sol. (a) It is given that emf of the battery , E = 12
Resistance of the bulb, R = 24ohm
Where switch is turned on, current through the bulb is I = E/R = 12/ 24= 0.5A
Hence, reading of ammeter is 0.5 A.
Q.8 Which one of the following statement is not correct?
(a) In steady flow of a liquid the velocity of liquid particles reaching a particular point is the same at all points
(b) Steady flow is also called streamlined flow
(c) In study flow each particle minute follow the same path as taken by a previous particle passing through that point
(d) Two streamlines cannot intersect with each other
Sol. (c) In steady flow, the velocity of fluid particles reaching at a particular at all time .Thus, each particle follows the same path as taken by a previous particle passing through that point. Therefore, two streamlines cannot intersect with each other.
Q.9 The loudness of sound is related to ?
(a) Its frequency
(b) Its amplitude
(c) Its speed
(d) Its pitch
Sol. (b) the amplitude of a sound wave determines its loudness. A larger amplitude means a louder sound and smaller amplitude means a software sound which and frequency are related with shrillness of sound
Q.10 Which one of the following circuit elements is an active component ?
(a) Resistor
(b) Transistor
(c) Inductor
(d) Capacitor
