KVPY StreamSA (Class 11) Physics: Questions 180  185 of 252
Get 1 year subscription: Access detailed explanations (illustrated with images and videos) to 252 questions. Access all new questions we will add tracking exampattern and syllabus changes. View Sample Explanation or View Features.
Rs. 200.00 or
Question number: 180
» Electrostatics » Coulomb's Law
Question
The excess (equal in number) of electrons that must be placed on each of two small sphered 3 cm apart with force of repulsion between sphere to be 10^{19} N, is
Choices
Choice (4)  Response  

a.  125 

b.  625 

c.  25 

d.  50 

Question number: 181
» Electronic Devices » Junction Transistor
Question
In a PNP transistor circuit the collector current is 30 mA. If 75 % of the electrons emitted reach the collector, the value of α and I_{B} are respectively –
Choices
Choice (4)  Response  

a.  0.85, 5 

b.  0.6, 7 

c.  0.75, 10 

d.  0.7, 11 

Question number: 182
Question
40 sheets of mica, each of thickness 0.3 mm are interspersed with aluminum foils of area 35 cm^{2}. The metal sheets are connected alternately to form a system of capacitors. The capacitance of the capacitor is –
Choices
Choice (4)  Response  

a. 


b. 


c. 


d. 


Question number: 183
Question
In a concave mirror, an object is placed at a distance 12 cm from the focus and its image is formed at a distance 3 cm from the focus. The focal length of the mirror is,
Choices
Choice (4)  Response  

a.  4 cm 

b.  5 cm 

c.  6 cm 

d.  3 cm 

Question number: 184
» Ray Optics » Power of a Lens
Question
A convex lens of focal length 21 cm and a concave lens of focal length 17 cm are placed in close contact with one another. The power of the combination is –
Choices
Choice (4)  Response  

a.  2.43 D 

b.  2.43 D 

c.  0.41 D 

d.  1.12 D 

Question number: 185
» Work, Energy and Power » Kinetic Energy
Question
A ball whose kinetic energy is E, is thrown at an angle of 60^{0} with the horizontal. Its kinetic energy at the highest point of its trajectory will be,
Choices
Choice (4)  Response  

a. 


b.  0 

c. 


d. 

