A fresh set of 20 random questions is generated every time you open this page and every time you refresh it.For each of the following multiple choice questions, choose the most appropriate answer :
1. lf A, Z and N denote the mass number , the atomic number and the neutron number for a given nucleus. then which of the following statement is incorrect?
A. isobar have the same A but different Z and N
B. isotopes have the same Z but different N and A
C. isotones have the same N but different A and Z
D. N = Z+A
2. A proton is about 1840 times heavier than an electron . When it is accelerated by potential difference of 1 kV, its kinetic energy will be
A. 1840 ke V
B. 1./1840 ke V
C. 1 ke V
D. 920 ke V
3. A neutron makes a head-on elastic collision with a stationary deuteron. The fractional energy loss of the neutron in the collision is
A. 16/81
B. 8/27
C. 8/9
D. 2/3
4. A proton of energy 4 eV is incident on a metal surface whose work function is 2 eV. The minimum reverse potential to be applied for stopping the emission of electrons is
A. 2V
B. 24V
C. 6V
D. 8V
5. Using mass M, length L, time T and current as fundamental quantities, the dimension of permeability is
A. M-1LT-2 A
B. ML 2T-2 A-1
C. ML T-2 A-2
D. ML T-1 A-1
6. A soap bubble is vacuum has a radius of 3 cm and another soap bubble in vacuum has a radius of 4cm. If the two bubbles coalesce under isothermal conditionals the radius of the new bubble will be
A. 7 cm
B. 5 cm
C. 4.5 cm
D. 2.3 cm
7. A parallel plate capacitor is made by stacking n equally spaced plates connected alternatively. If the capacitance between any two adjacent plates is C then the resultant capacitance is
A. n-1C
B. n+1C
C. C
D. nC
8. Which statement below is true ?
A. Radiant energ; is propagated as a wave motion
B. Positions have the same mass as an electron
C. When a nucleus emits a beta particle, its mass number is unchanged
D. All of ihe above
9. An astronaut is looking down on earth's surface from a space shuttle at an altitude of 400 km. Assuming that the astronaut's pupil diameter is 5 mm and the wavelength of visible light is 500 nm. The astronaut will be able to resolve linear objects of the size of about
A. 0.5 m
B. 5 m
C. 50 m
D. 500 m
10. If a body ‘A’ of mass ‘M’ is thrown with velocity ‘V’ at an angle of 30° to the horizontal and another body ‘B’ of the same mass is thrown with the same speed at an angle of 60° to the horizontal, the ratio of horizontal range of A to B will be?
A. 1:3
B. 1:1
C. 3:2
D. 2:3
11. If an electron and a photon propagate in the form of waves having the same wavelength, it implies that they have the same
A. Energy
B. Momentum
C. Velocity
D. Angular momentum
12. Which of the following relations between weber, second, ampere and volt is correct ?
A. weber/second = volt
B. weber x second = volt
C. weber/second = ampere
D. weber x second = ampere
13. The wavelength of light of a particular wavelength received from a galaxy is measured one earth and is found to be 5% more that its wavelength. It follows that the galaxy is
A. going away from the earth with a speed 1.5E7/ms
B. approaching the earth with a speed 1.5E7/ms
C. going away from the earth with a speed 3E7/ms
D. approaching the earth with a speed 3E7/ms
14. Speed of Electro Magnetic wave depends
A. only upon the electric properties of the medium
B. only upon the magnetic properties of the medium
C. both upon the electric and magnetic properties of the medium
D. mechanical and themial properties of the medium
15. When a beta-particle is emitted from a nucleus, the neutron-proton ratio
A. is increased
B. is decreased
C. remains the same
D. first decreases then increases
16. lf the uniform acceleration near the surface of the earth is about 9.8 m/sec for . free-fall, what is the velocity at the end of 2 seconds of fall ? neglect friction
A. 14.6 m/sec
B. 17.0 m/sec
C. 19.6 m/sec
D. 9.8 rn/sec
17. When a monochromatic point source of light is at a distance of 0.2 m from a photocell, the cutoff voltage and the saturation current are respectively Vo = 0.6 volt and is = 18.0 mA. If the same source is placed 0.6 m away from the photocell, then
A. Stopping potential Vo = 0.2 volt and saturation current is = 18.0 mA
B. Stopping potential Vo = 0.6 volt and saturation current is = 18.0 mA
C. Stopping potential Vo = 0.6 volt and saturation currenl is = 2.0 mA
D. Stopping potential Vo = 0,2 volt and saturation current is=2.0mA
18. Two rods of the same length and material transfer a given amount of heat in 12 seconds when they are joined end to end. But when they are joined length-wise, they will transfer the same amount of heat, in the same conditions, in
A. 1.5s
B. 48s
C. 24s
D. 3s
19. A bullet is fired from a gun with a speed of 1000 m/s in order to hit a target 100 m away. At what height above the target should the gun be aimed? The resistance of air is negligible and g=10 m/s2
A. 5 cm
B. 10 cm
C. 15 cm
D. 20 cm
20. A proton and an alpha - particle, moving with the same velocity. enter into a uniform magnetic field, acting normal to the plane of their motion. The ratio of the radii of the circular paths described by the proton and alpha - particle is
A. 1:2
B. 1:4
C. 1:16
D. 4:1
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