Heat supplied $d Q=$ increased in internal energy dU is true for
With a resistance ' X ' connected in series with a galvanometer of resistance $100 \Omega$, it acts as a voltmeter of range $0-15 \mathrm{~V}$. To double the range, a resistance of $1500 \Omega$ is to be connected in series with ' X '. The value of ' X ' in ohm is
When one end of a capillary tube is dipped in water, the height of water column is ' $h$ '. The upward force of 105 dyne due to surface tension is balanced by the force due to the weight of water column. The inner circumference of the capillary tube is
(Surface tension of water $=7 \times 10^{-2} \mathrm{~N} / \mathrm{m}$ )
A tuning fork gives 5 beats per second with 40 cm length of sonometer wire. If the length of the wire is shortened by 1 cm , the number of beats is still the same. The frequency of the fork is