Practice Physics ncert - general science mcq Online Quiz (set-1) For All Competitive Exams

Q-1)   The waves used in telecommunication are

(a)

(b)

(c)

(d)

Q-2)   At absolute zero, Si acts as

(a)

(b)

(c)

(d)

Q-3)   Sun emits energy in the form of electromagnetic radiation. The following help in the generation of solar energy. Arrange them in the right sequence beginning from the starting of the cycle :
  1. Hydrogen is converted to helium at very high temperatures and pressures.
  2. The energy finds its way to sun's surface.
  3. A vast quantity of energy is generated by nuclear fusion.
Select the correct answer using the code given below.

(a)

(b)

(c)

(d)

Q-4)   Which part of the solar cooker is responsible for green house effect?

(a)

(b)

(c)

(d)

Q-5)   Chadwick was awarded the 1935 nobel prize in physics for his discovery of the

(a)

(b)

(c)

(d)

Q-6)   At the present level of technology available in India, solar energy can be conveniently used to :
  1. Supply hot water to residential buildings.
  2. Supply water for minor irrigation projects.
  3. Provide street lighting.
  4. Electrify a cluster of villages and small towns.
Which of the statements given above are correct?

(a)

(b)

(c)

(d)

Explanation:

Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies.

At present solar energy in our country is used for solar water heater.

Solar lights that charge during the day and light up at night are a common sight along walkways.

Q-7)   If an a-particle is projected normally through a uniform magnetic field, then the path of the a-particle inside the field will be

(a)

(b)

(c)

(d)

Q-8)   Consider the following statements: In a nuclear reactor, self-sustained chain reaction is possible, because:
  1. More neutrons are released in each of the fission reactions.
  2. The neutrons immediately take part in the fission process.
  3. The fast neutrons are slowed down by graphite.
  4. Every neutron released in the fission reaction initiates further fission.
Which of the statements given above are correct?

(a)

(b)

(c)

(d)

Explanation:

A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. The most common use of nuclear reactors is for the generation of electrical power and for the power in some ships.

In every fission reaction in which uranium nuclei splits up to give smaller nuclei three more neutrons are produced which further results into splitting of heavy uranium nuclei and more number of neutrons will be produced.

Thus, statement, 1 & 2 are correct.

In nuclear reactor all the neutrons produced can not take part in fission reaction, else reaction can turn out extremely violent. Thus, graphite rods are used as a control rods to slow down the speed of fast moving neutrons. Thus, statement 3 is also correct.

Q-9)   The active component in an IC are

(a)

(b)

(c)

(d)

Q-10)   Which one among the following radiations carries maximum energy?

(a)

(b)

(c)

(d)

Q-11)   Television signals are

(a)

(b)

(c)

(d)

Q-12)   A perfect black body has the unique characteristic feature as

(a)

(b)

(c)

(d)

Q-13)   Consider the following statements: At the present level of technology available in India, solar energy can be conveniently used to :
  1. Supply hot water to residential buildings.
  2. Supply water for minor irrigation projects.
  3. Provide street lighting.
  4. Electrify a cluster of villages and small towns.

(a)

(b)

(c)

(d)

Explanation:

Q-14)   A moderator is used in nuclear reactors in order to

(a)

(b)

(c)

(d)

Q-15)   Which of the following cannot be fabricated on an IC?

(a)

(b)

(c)

(d)

Q-16)   Match the List I and List II.
List I List II
A. Nebulae 1. Highly dense matter available in the atmosphere
B. Stratosphere 2. Layer of the atmosphere
C. Black hole 3. Ursa major
D. Saptarishi 4. The clouds of dusty gases
Select the correct answer using the codes given below the lists:

(a)

(b)

(c)

(d)

Explanation:

A → 4;

B → 2;

C → 3;

D → 1. 

Q-17)   Match the List I and List II.
List I List II
A. Rectifier 1. Convert information into electrical signal
B. Inverter 2. Convert AC into DC
C. Zener diode 3. Convert DC into AC
D. Transducer 4. Voltage stabilization
Select the correct answer using the codes given below the lists:

(a)

(b)

(c)

(d)

Explanation:

A → 2; B → 3; C → 4; D → 1

  1. Rectifier is used to convert AC signals into DC signals.
  2. Inverter is used to convert DC signals into AC signals.
  3. Zener diode is the highly doped diode in which reverse current increases very sharply. It can operate continuously without damaging the junction, so it is used for voltage stabilisation.
  4. Transducer is a device that converts one form of energy into another Microphones, photodetectors and piezoelectric sensors are types of transducers. They convert information into electrical signals.

Q-18)   Which one of the following is correct? The wavelength of the X-rays

(a)

(b)

(c)

(d)

Q-19)   Audio signal cannot be transmitted because

(a)

(b)

(c)

(d)

Q-20)   Audio signal cannot be transmitted because:

(a)

(b)

(c)

(d)

Explanation:

Following are the problems which are faced while transmitting audio signals directly.

  1. These signals are relatively of short range.
  2. If every body started transmitting these low frequency signals directly, mutual interference will render all of them ineffective.
  3. Size of antenna required for their efficient radiation would be larger i.e. about 75 km.