A lit of mass M=0.8 ton is raised to a height h=40m in t=0.5min. The voltage across the motar terminals is V=220V and the motar efficiency `eta=90%`. Find the power an current consumed by the motar and the price of one hoisting if B.O.T. costs 60 paise.
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A student is able to throw a ball vertically to maximum height of 40m. The maximum distance to which the student can throw the ball in the horizonal d
Correct Answer - D `H_("max")=(u^(2))/(2g)=40 rArr (u^(2))/(g)=80` `R_("max")=(u^(2))/(g)=80m`
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An electric heater and an electric bulb are rated 500W. 220V and 100W, 220V respectively. Both are connected in series to a 220V d.c. mains. Calculate
`P=(V^(2))/(R)` or `R=(V^(2))/(P)` For heter, Resistane `R_(h)=((220)^(2))/(500)=96.8Omega` For bulb resistance `R_(1)=((220)^(2))/(100)=484Omega` Current in the circuit when both are connected in series `I=(V)/(R_(L)+R_(h))=(220)/(484+96.8)=0.38A` (i) power consumed by heater `=I^(2)P_(h)=(0.38)^(2)xx96.8=13.98W` (ii) Power...
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A light bulb is rated 100W for a 220V supply. The resistance of the bulb and the peak voltage of the source respectively are
Resistance of a bulb`=(("Rated voltage")^(2))/("Rated power")` `=((220)^(2))/(100)=484Omega` Peak voltage of the source. `V_(0)=220sqrt(2)V=311V`
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When the modified galvanometer of exercise 26 is connected across the terminals of a battery, it shows a current of 4A. The current drops to 1A when a
Correct Answer - `0.49Omega,2V`
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A resistor R and `2muF` capacitor in series are connected to a 220V dc supply. Across the capacitor is a neon bulb that strikes at 120V. Calculate the
Correct Answer - `2.73 MOmega`
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The terminals of a cell are cnnected to resistance R and the falll of potential across R is balaced against the fall of potential on a potentiometer w
Correct Answer - 6.67 `Omega`
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An 220V AC voltage at a frequency of 40 cycles/s is applied to a circuit containing a pure inductance of 0.01H and a pure resistance of `6 Omega` in s
Correct Answer - `(a) 33.83 mA (b) 202.98 V (c ) 96.83 V (d) 0.01579 s`
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A nuclear reactor generates `P = 20 MW` power at efficiency `eta = 60%` by nuclear fission of a radio-nuclide whose half life is `T = 2.2` years. If e
Correct Answer - `[(T)/(ln 2)ln(1+(mu N eta Eln 2)/(PT)) = 10^(8) ln (1.0576)s]`
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The potential differnce between the terminals of a battery of emf 6.0 V and internal resistance `1 Omega` drops to 5.8 V when connected across an exte
Correct Answer - `29 Omega`
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When a resistance of `2 Omega` is placed across the terminals of a battery, the current is 0.5 A. When the resistance across the terminals of the batt
Correct Answer - `1.5 V, 1 Omega`
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