Physics Selected Questions and Answers Set 9

Q.1:- A lesser beam is always ?

1. A convergent beam
2. A divergent beam
3. A parallel beam
4. Divergent to start with an parallel later on

Q.2:- Total internal reflection occurs when light travels from ?

1. A denser medium to a rarer medium with angle of incidence greater than critical angle
2. A rarer medium to a denser medium
3. A denser medium to a rarer medium
4. A rarer medium to a denser medium with angle of incidence greater than critical angle

Q.3:- An electron microscope gives higher magnifications than an optical microscope because ?

1. The electrons have more energy than the light particles
2. The electron microscope uses more powerful lenses
3. The wavelength of electrons is smaller as compared to the wavelength of visible light
4. The velocity of electrons is smaller than that of light

Q.4:- A plane glass slab is kept over coloured letters, the letter which appears least raised is ?

1. Green
2. Violet
3. Red
4. Blue

Q.5:- The conductivity of superconductor is ?

1. Infinite
2. Very Large
3. Very Small
4. Zero

Q.6:- Metals are good conductor of heat than insulator because ?

1. Their atoms are relatively apart
2. They contain free electron
3. They have reflecting surface
4. None of these

Q.7:- The primary cell is a ?

1. Secondary cell
2. Primary cell
3. Both (a) and (b)
4. None of these

Q.8:- A switch is always connected to the ?

1. Earth wire
2. Neutral wire
3. Line wire
4. None of these

Q.9:- If the current in the core decreases, the strength of the magnetic field ?

1. Decreases
2. Increases
3. Remains same
4. None of these

Q.10:- The wire having black plastic covering is a ?

1. Line wire
2. Neutral wire
3. Earth wire
4. None of these

Q.11:- The wire having a red plastic covering is a ?

1. Line wire
2. Neutral wire
3. Earth wire
4. None of these

Q.12:- An atomic pile is ued for ?

1. Producing X-rays
2. Conducting nuclear fission
3. Conducting thermonuclear fission
4. Temperature

Q.13:- Fusion reaction takes place at high temperature because ?

1. Atoms are ionized at high temperature
2. Molecules break up at high temperature
3. Nuclei break up at high temperature
4. Kinetic energy is high enough to overcome repulsion at high temperature

Q.14:- Which of the particles has similar mass to that of the electron ?

1. Proton
2. Neutron
3. Positron
4. Neutrino

Q.15:- Resistivity of semiconductor depends on ?

1. Shape of semiconductor
2. Length of semiconductor
3. Atomic nature of semiconductor
4. Shape and atomic nature of semiconductor

Q.16:- Who invented the mobile phone ?

1. Raymond Samuel Tomlinson
2. Marlin Cooper
3. Chuck Hull
4. Tim Berners-Lee

Q.17:- Which of the following device is full duplex ?

1. Mobile phone
2. Walky-talky
3. Loudspeaker
4. Radio

Q.18:- A digital signal possesses ?

1. Continuously varying values
2. Only two discrete values
3. Only four discrete values
4. None of the above

Q.19:- Heat energy of an object is ?

1. The average energy of the molecules of the object ?
2. The total energy of the molecules of the object
3. The average velocity of the molecules of the object
4. The average P.E. of the molecules of the object

Q.20:- The temperature of a gas is measured with a ?

1. Platinum resistance thermometer
2. Pyrometer
3. Gas thermometer
4. Vapour pressure thermometer

Q.21:- Which of the following is a scalar quantity ?

1. Velocity
2. Force
3. Angular momentum
4. Electrostatic potential

Q.22:- At which of the following locations the value of ‘g’ is the largest ?

1. On top of Mount Everest
2. On top of Qutub Minar
3. At a place on Equator
4. A camp site in Antarctica

Q.23:- If the radius of the earth were shrink by one percent, its mass remaining the same, the value of g on the earth’s surface would.

1. Increase by 0.5%
2. Increase by 2%
3. Decrease by 0.5%
4. Decrease by 2%

Q.24:- Newton’s first law is also called as ?

1. Law of moments
2. Law of inertia
3. Law of momentum
4. Law of energy

Q.25:- Meniscus of mercury in a capillary is ?

1. Concave
2. Convex
3. Plane
4. Cylindrical