Current Electri...

A lead acid battery of a car has an emf of 12 V. If the internal resistance of the battery is 0.5 Ω, the maximum current that can be drawn from the battery will be

An electric circuit contains an operating heating element and a lit lamp. Which statement best explains why the lamp remains lit when the heating element is removed from the circuit?

A 50Ω galvanometer gets full scale deflection when a current of 0.01 A pass through the coil. When it is converted to a 10 A ammeter, the shunt resistance is

Two electric bulbs marked 25 W–220 V and 100 W–200 V are connected in series to a 440 V supply. Which of the bulbs will fuse?

An electric bulb marked as 50 W–200 V is connected across a 100 V supply. The present power of the bulb is

Heat is produced at a rate given by H in a resistor when it is connected across a supply of voltage V. If now the resistance of the resistor is doubled and the supply voltage is made V/3, then the rate of production of heat in the resistor will be

A heating coil is used to heat water in a container from 15°C to 50°C in 20 min. Two such coils are then joined in series to heat the same amount of water for the same temperature difference from the same constant voltage source. The time taken now is

When two identical batteries of internal resistance 1Ω each are connected in series across a resistor R, the rate of heat produced in R is J₁. When the same batteries are conected in parallel across R, the rate is J₂. If J₁ = 2.25 J₂, then the value of R in Ω is

A resistor R and 2μF capacitor in series is connected through a switch to 200 V direct supply. Across the capacitor is a neon bulb that lights up at 120 V. Calculate the value of R to make the bulb light up 5 s after the switch has been closed (log₁₀ 2.5 = 0.4)

The resistance of the filament of a lamp increases with the increase in temperature. A lamp rated 100 W and 200 V is connected across 220 V power supply. If the voltage drops by 10%, then the power of the lamp will be