Physics, asked by Anonymous, 1 year ago

Solve question 10,12,15....

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Answered by havas2

14)A)In audio signal processing and acoustics, echo is a reflection of sound that ... When a sound produces an echo in two seconds, the reflecting object is 343m away

Anonymous: I did not ask the 14th one

Anonymous: Pls answer the 10th 12th and 15th

eroses2: 15.no. maybe B is right

atharva13: 15)Its be parallel connection.because when you open a switch of fan only fan gets started not all appliances in home .But when you go in factory (any) when workers press only one switch alot of applliances get started.Over there it is in series connection

atharva13: its 'B'*

Answered by Silverbolt

Ans 10. (B)

As the bulbs are connected in parallel, their equivalent power P = (100+60) = 160 watt.

∴ Equivalent resistance R = V²/P = (220)²/160 = 302.5 Ω.

∴Current drawn from supply line I = V/R = 220/302.5 = 0.727 A. (Ans B)

Ans 12.(D)

Speed of first person = 4.5 km/hr = 1.25 m/s.
Speed of second person = 1.5 km/hr = 1.5 m/s.
Let speed of train be v m/s.
Relative speed of 1st and 2nd person with respect to train = (v-1.25)m/s and (v-1.5)m/s.

In both cases, length of train = relative speed×time taken to overtake.

∴ By the problem, we get,
(v-1.25)×8.4=(v-1.5)×8.5
Solving, we get, v= 22.5 m/s = 81 km/hr.(Ans D)

Ans 15.(B)

Parallel combination , since all appliances may not be switched on simultaneously.

HOPE IT HELPS!!! :)

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