# Physics General Knowledge Questions and Answers – Section 1

Q1. Which of the statement is incorrect about the simple microscope?
A. Magnification of microscope is inversely proportional to the least distance of distinct vision.
B. A convex lens of microscope with shorter focal length yields higher magnification.
C. Biology students use to see the slides.
D. It is not used for magnification of an object at far away from the observer.

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Answer: (A) Magnification of microscope is inversely proportional to the least distance of distinct vision.

Q2. Suppose you drive to Delhi (200 km away) at 400 km/hr and return at 200 km/hr. What is yours average speed for the entire trip?
A. Zero
B. 300 Km/hr
C. Less than 300 Km/hr
D. More than 300 Km/hr

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Answer: (C)Less than 300 km/hr

Q3. A system undergoes a reversible adiabatic process. The entropy of the system
A. increases
B. decreases
C. remains constant
D. may increase or may decrease

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Answer: (C) remains constant

Q4. A narrow white light beam fails to converge at a point after going through a converging lens. This defect is known as
A. polarization
B. spherical aberration
C. chromatic aberration
D. diffraction

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Answer: (C) chromatic aberration

Q5. In a room where the temperature is 30°C a body cools from 61°C to 59°C in 4 minutes. The time taken by the body to cool from 51°C to 49°C will be about
A. 4 minutes
B. 6 minutes
C. 5 minutes
D. 8 minutes

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Answer: (B)6 minutes

Q6. A student’s 9.0 V, 7.5W portable radio was left on from 9:00 P.M. until 3:00 A.M. How much charge passed through the wires?
A. 6000C
B. 12000C
C. 18000C
D. 24000C

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Answer: (C)18000C

Q7. An 1800 W toaster, a 1.3KW electric fan and a 100W lamp are plugged in the same 120V circuit i.e. all the three devices are in parallel. What is the approximate value of the total current (i.e. sum of the current drawn by the three devices) through circuit ?
A. 18A
B. 27A
C. 40A
D. 120A

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Answer: (B)27A

Q8. If the current in the toroidal solenoid increases uniformly from zero to 6.0A in 3.0μs. Self inductance of the toroidal solenoid is 40μH. The magnitude of self induced emf is
A. 24V
B. 48V
C. 80V
D. 160V

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Answer: (B) 24V

Q9. An electron is at ground state of the H atom. Minimum energy required to excite the H atom into second excited state is
A. 10.2eV
B. 3.4eV
C. 13.6eV
D. 12.1eV

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Answer: (C)80V

Q10. A particle enters uniform constant magnetic field region with its initial velocity parallel to the field direction. Which of the following statements about its velocity is correct? (neglect the effects of other fields)
A. There is change only in magnitude
B. There is change only in direction
C. There is change in both magnitude and direction
D. There is no change

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Answer: (D) There is no change

Q11. Which of the following Material has lowest resistivity?
A. Constantan
B. Silver
C. Manganin
D. Copper

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Answer: (B)Silver

Q12. A particle is moving in translatory motion. If momentum of the particle decreases by 10%, kinetic energy will decrease by
A. 20%
B. 19%
C. 10%
D. 5%

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Answer: (B) 19%