Physics Selected Questions and Answers Set 6

Q.1:- Distance of stars measured in ?

1. Galactic Unit
2. Seller Mile
3. Cosmic Kilometre
4. Light Year

Ans:- (d) Light Year

Q.2:- Water drops do not stick to the oily surface due to ?

1. Lack of adhesive force
2. Surface tension
3. Cannot mix each other
4. Water is lighter than oil

Ans:- (a) Lack of adhesive force

Q.3:- A bullet hits and gets embedded in a solid block resting on a horizontal frictionless table. Which physical quantity is conserved in this process ?

1. Momentum and kinetic energy
2. Momentum alone
3. Kinetic energy alone
4. Neither momentum nor kinetic energy

Ans:- (b) Momentum alone

Q.4:- A liquid drop attains spherical shape due to ?

1. Surface tension
2. Viscosity
3. Upward thrust
4. Gravitation

Ans:- (a) Surface tension

Q.5:- The product of the pressure and volume of an ideal gas is ?

1. A constant
2. Approximately equal to the universal gas constant
3. Directly proportional to its temp
4. Inversely proportional to its temp

Ans:- (c) Directly proportional to its temp

Q.6:- A metal sheet with circular hole is heated. The hole will ?

1. Contract
2. Expand
3. Remain unaffected
4. None of these

Ans:- (b) Expand

Q.7:- Decibel is a ?

1. Musical Note
2. Musical Instrument
3. Unit of Intensity
4. None of the above

Ans:- (c) Unit of Intensity

Q.8:- If the mass of the pendulum is doubled, the time period ?

1. Becomes double
2. Becomes half
3. Becomes four times
4. Remains same

Ans:- (d) Remains same

Q.9:- With the rise of temperature, the speed of sound in a gas ?

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

Ans:- (a) Increases

Q.10:- The loudness of sound depends upon ?

1. Velocity
2. Pitch
3. Amplitude
4. Wavelength

Ans:- (c) Amplitude

Q.11:- Different objects at different distances are seen by the eye. The parameter that remain constant is ?

1. The focal length of the eye lens
2. The object distance from the eye lens
3. The radii of curvature of the eye lens
4. The image distance from the eye lens

Ans:- (d) The image distance from the eye lens

Q.12:- In the human eye, the focussing is done by ?

1. To and fro movement of the eye lens
2. To and fro movement of the retina
3. Change in the convexity of the eye lens
4. Change in the refractive index of the eye fluids

Ans:- (c) Change in the convexity of the eye lens

Q.13:- The chemical part of the dye that absorbs light and produces colour is called ?

1. Neon
2. A Chromophore
3. A Photochrome
4. A Pigment

Ans:- (d) A Pigment

Q.14:- Diffusion of light in the atmosphere takes place due to ?

1. Carbon dioxide
2. Dust particles
3. Helium
4. Water vapours

Ans:- (b) Dust particles

Q.15:- An air bubble in water will act like a ?

1. Convex mirror
2. Convex lens
3. Concave mirror
4. Concave lens

Ans:- (d) Concave lens

Q.16:- Light from the Sun reaches upon in nearly ?

1. 8 min
2. 2 min
3. 6 min
4. 4 min

Ans:- (a) 8 min

Q.17:- A plant with green leaves placed in red light will appear ?

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

Ans:- (c) Black

Q.18:- Optic fibres are mainly used for which of the following ?

1. Musical instruments
2. Food industry
3. Weaving
4. Communication

Ans:- (d) Communication

Q.19:- Kirchhoff’s voltage law is based on the law of conservation of ?

1. Momentum
2. Charge
3. Mass
4. Energy

Ans:- (d) Energy

Q.20:- Electric current is measured using which of the following instrument ?

1. Anemometer
2. Ammeter
3. Voltmeter
4. Wattmeter

Ans:- (b) Ammeter

Q.21:- Tangent galvanometer is used to measure ?

1. Steady currents
2. Currents impulses
3. Earth’s magnetic field
4. None of these

Ans:- (a) Steady currents

Q.22:- A magnetic needle is kept in non-uniform magnetic field. It experiences ?

1. A force and a torque
2. A force but not a torque
3. A torque but not a force
4. None of these

Ans:- (a) A force and a torque

Q.23:- Fleming’s right hand rule gives ?

1. The magnitude of the induced emf
2. The magnitude of the magnetic field
3. The direction of the induced emf
4. None of these

Ans:- (c) The direction of the induced emf

Q.24:- Good conductors have many loosely bound ?

1. Protons
2. Neutrons
3. Atoms
4. Electrons

Ans:- (d) Electrons

Q.25:- In electric supply lines in India, which parameter is kept constant ?

1. Voltage
2. Current
3. Frequency
4. Power

Ans:- (c) Frequency