KVPY (Kishore Vaigyanik Protsahan Yojana) StreamSA (Class 11) Physics: Questions 19  22 of 253
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Question number: 19
» Oscillations and Waves » Periodic Motion  Period Frequency
Appeared in Year: 2010
Question
A hollow pendulum bob filled with water has a small hole at the bottom through which water escapes at a constant rate. Which of the following statements describes the variation of the time period (T) of the pendulum as the water flows out?
Choices
Choice (4)  Response  

a.  T decreases first and then increases 

b.  T does not change 

c.  T increases throughout 

d.  T increases first and then decreases 

Question number: 20
» Kinematics » Relative Velocity
Appeared in Year: 2011
Question
A girl standing at point P on a beach wishes to reach a point Q in the sea as quickly as possible. She can run at 6 km h ^{–1} on the beach and swim at 4 km h ^{–1} in the sea. She should take the path,
Choices
Choice (4)  Response  

a.  PCQ 

b.  PDQ 

c.  PAQ 

d.  PBQ 

Question number: 21
» Ray Optics » Reflection and Refraction of Light
Appeared in Year: 2010
Write in Short
A point source is placed 20 cm to the left of a concave lens of focal length 10 cm.
(a) Where is the image formed?
(b) Where to the right of the lens would you place a concave mirror of focal length 5 cm such that the final image is coincident with the source?
Question number: 22
» Current Electricity » Electrical Resistance
Write in Short
Consider the two circuits P and Q, shown below, which are used 20 measure the unknown resistance R.
In each case, the resistance is estimated by using Ohm’s law , Where V and I are the readings of the voltmeters and the ammeters respectively. The internal resistances of voltmeter and ammeter are R _{V} and R _{A}, such that R _{A} < < R < < R _{V}.
The internal resistance of the battery may be ignored. The absolute error in the estimate of the resistance is denoted by δ R = R  Rest .
(a) Express δ R _{P} in terms of the given resistance values
(b) Express δ R _{Q} in terms of the given resistance values
(c) For what value of R will δ R _{P } ≈ δ R _{Q}