Given that the resistivity of Gold and Platinum is 2.1 x 10^-8 ohm.m and 10.5 x 10^-8 ohm.m, respectively, which is the correct statement?

Statement A : 5 metres of platinum wire will have the same resistance as one metre of gold wire.

Statement B : Gold wire of 1 cm radius will have the same resistance as platinum wire of 5 cm radius.

1. Only statement A is correct.
2. Only statement B is correct.
3. Both statements A and B are correct.
4. Both statements A and B are incorrect.

Assertion (A) : A switch will serve the purpose of making and breaking a circuit when it is connected to the neutral wire.

Reason(R) : Neutral wire is at zero potential.

1. Both Assertion and Reason are true, and the Reason is the correct explanation of the Assertion
2. Both Assertion and Reason are true, but Reason is not the correct explanation of the Assertion
3. Assertion is true, but the Reason is false.
4. Both Assertion & Reason are false.

Which of the following equations are correctly balanced?

$\bold{A.} \quad \phantom{X}^{q-1}${p-5}X \longrightarrow \phantom{X}^{q-5}{p-3}Y + \phantom{X}^{4}{2}He \\[1em] \bold{B.} \quad \phantom{X}^{q-4}{p-4}Z \longrightarrow \phantom{X}^{q-4}{p-5}X + \phantom{X}^{\phantom{1}0}{-1}e \\[1em] \bold{C.} \quad \phantom{X}^{q-1}{p-5}X \longrightarrow \phantom{X}^{q-5}{p-7}Y + \phantom{X}^{4}{2}He \\[1em] \bold{D.} \quad \phantom{X}^{q-4}{p-7}Z \longrightarrow \phantom{X}^{q-4}{p-5}X + \phantom{X}2^{\phantom{1}0}{-1}e \\[1em]

1. Only D
2. Only C
3. Both A & B
4. Both C & D

The below picture shows three cylinders filled with water to a different extent. The tuning forks L, M and N in vibration produce louder sound when held above the mouth of the cylinders. Which combination is correct for hearing a louder sound of the tuning fork?

1. L – R, M – Q, N – P
2. L – P, M – Q, N – R
3. L – R, M – P, N – Q
4. L – Q, M – R, N – P