$A$ sound absorber attenuates the sound level by $20\, dB$. The intensity decreases by a factor of

In the circuit shown,the reading of the Ammeter is doubled after the switch is closed. Each resistor has a resistance $= 1\,\Omega$ and the ideal cell has an $e.m.f. = 10\,V$. Then,the Ammeter has a coil resistance equal to .............. $\Omega$.

$A$ galvanometer,having a resistance of $50 \,\Omega$,gives a full-scale deflection for a current of $0.05 \,A$. The length in meters of a resistance wire of cross-sectional area $2.97 \times 10^{-2} \,cm^2$ that can be used to convert the galvanometer into an ammeter which can read a maximum of $5 \,A$ current is (Specific resistance of the wire = $5 \times 10^{-7} \,\Omega \cdot m$)

Data Entry - Physics

Pollen grains of a plant,whose $2n = 28$,are cultured to get callus by tissue culture method. What would be the number of chromosomes in the cells of the callus?

When $NaCl$ is dissolved in water,the sodium ion becomes