In a house there are ten 60-watt lamps. Three 40-watt flourorescent tubes and three 40-watt fans. When all these are switched on what is the current drawn from the mains if the supply voltage is 220V? Calculate the power drawn and the cost for using them for 6hours daily in a month of 30 days.( 1 B.O.T. unit costs 30 pasise).
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A coil draws a current of `1.0` ampere and a power of `100` watt from an `A.C.` source of `110` volts and `(5sqrt22)/pi` hertz. Find the inductance an
Correct Answer - `sqrt(21/22)H-100 Omega` `I_(rms)^(2)xxR=100` --(1) `(1)^(2)xxR=100 rArrR=100 Omega` `V_(rms)=I_(rms)Z , 110=I_(rms)Z , 110=1xxZ=sqrt(R^(2)+(omegaL)^(2)) , L=sqrt(21/22)H`
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Since 1891 lighting lamps have been manufactured in the Netherlands. The improvement today in comparison to the first lamp is enormous , especially wi
Correct Answer - `H_(1) =- (139 xx 3xx1xx2.958)/(0.297) xx (10)/(11) KJ mol^(-1)` `H_(e) =(-3 xx(139xx3xx1)/(0.294)xx(10)/(11)) + (3 xx (139 xx1xx1)/(0.297sqrt(3))xx(10)/(11)) KJ "mol"^(-1) =-3092 KJ "mol"^(-1)` `H_(3) =(-3 xx(139 xx 3xx1)/(0.297)xx(10/(11))...
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There are 20 cards. Ten of these cards have the letter `"I"` printed on them and the other 10 have the letter `"I"` printed on them. If three cards pi
Correct Answer - B Consider the following events : A: getting a card with mark I in first draw B: getting a card with marks I in second draw C: getting...
2 Answers 1 views
In the last question, the electric field in vertical direction is switched off and a field of same strength`(E_0)` is switched on in horizontal direct
Correct Answer - `V_(xn)=(qE)/(m)sqrt((2h)/(g))[1+2e((1-e^(n-1))/(1-e))}` and `T=2e^(n)sqrt((2h)/(g))`
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An infinite number of lamps, each of luminous intensity 100 cd are placed 1 m apart in a horizontal line perpendicular to a wall. The nearest being 1
Correct Answer - `164.5 lux`
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street lamps of 10 cm diameter and `1.8xx10^(5)cdm^(2)` luminance are suspended at a height of 12 m the distance bewteen them being 40 m Find the illu
Correct Answer - `10.38 lux, 2.7 lux`
2 Answers 1 views
An electric kettle has two windings. When one of the n is switched on the kettle begins to boil in `t_(1)` minutes and when the other is switched on i
Correct Answer - `t_(1)+t_(2),(t_(1)t_(2))/(t_(1)+t_(2))`
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A standard 40W tubelight is in parallel with a room heater both connected to a suitable supply line. What will happen when the light is switched of:
In a parallel connection, if one of the devices is switched off then the other will not be affected. However, this is not the case with series connections. Thus, C...
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Two lamps of illuminating powers 25 cd and 100 cd are placed at the end of a photometer bench 2.0 m long. At what point on the bench will the screen o
Correct Answer - 0.67 m for 25 cd lamp
2 Answers 2 views
A person of mass 40 kg picked up a bag of mangoes and climbed ten steps . If the bag contains ten mangoes , each of mass `0.5` kg and the height of ea
Correct Answer - 450 J
2 Answers 1 views