The effect due to a uniform magnetic field on a freely suspended magnetic needle is as follows:

Doping silicon with boron produces a

How many integuments surround the ovule in $Pinus$ and $Cycas$?

One ampere of current is passed for $9650 \ s$ through molten $AlCl_3$. What is the weight in grams of $Al$ deposited at cathode? (atomic weight of $Al = 27$)

The binding energy of deuteron ${}_1^2H$ is $1.112 \text{ MeV}$ per nucleon and an $\alpha$-particle ${}_2^4He$ has a binding energy of $7.047 \text{ MeV}$ per nucleon. Then in the fusion reaction ${}_1^2H + {}_1^2H \to {}_2^4He + Q$,the energy $Q$ released is ........... $\text{MeV}$.

Steam at $100^{\circ} C$ is passed into $1 \ kg$ of water contained in a calorimeter of water equivalent $0.2 \ kg$ at $9^{\circ} C$ until the temperature of the calorimeter and water in it increases to $90^{\circ} C$. The mass of steam condensed in $kg$ is nearly (specific heat of water $= 1 \ cal/g^{\circ} C$,latent heat of vaporisation $= 540 \ cal/g$)