A car is moving towards a high cliff. The car driver sounds a horn of frequency \(f\). The reflected sound heard by the driver has a frequency \(2 f\). If \(v\) be the velocity of sound, then the velocity of the car in the same velocity units, will be

A proton is moving along negative X axis. If a uniform magnetic field is applied parallel to the positive Z axis, then choose the correct answer from the following options;
1. The proton will experience magnetic force along positive Y direction and will move along a circular path in the XY plane
2. The proton will experience magnetic force along negative Y direction and will move along a circular path in the XY plane
3. The proton will experience magnetic force along positive Y direction and will move along a circular path in the XZ plane
4. The proton will experience magnetic force along negative Y direction and will move along a circular path in the XZ plane

An object is dropped from a certain point A at a height 'h' from the ground. During it's journey straight downwards, the object passes points B and C such that the ratio of time taken \(t_1\) to cover AB and \(t_2\) to cover BC is 1: \((\sqrt{2} - 1)\). What is the ratio of distances AB:BC ?

A straight wire of mass 250 g and length 2.5 m carries a current of 4 A . It can be suspended in mid air by a uniform horizontal magnetic field of magnitude:

The amount of energy required to separate a hydrogen atom into a proton and an electron is

Three point charges are located on a circular arc at A, B and C as shown in the figure below. The total electric field at the centre of the arc (0) is

When unpolarised light beam is incident from air onto glass \((n=1.5)\) at the polarising angle

Effective capacitance between \(A\) and \(B\) in the figure shown is (all capacitances are in \(\mu \mathrm{F}\) )

A statement of Assertion followed by a statement of Reason is given.
Choose the correct answer out of the following options.
Assertion : Energy of \(2 \mathrm{~s}\) orbital of Hydrogen is less than the energy of the \(2 \mathrm{~s}\) orbital of Lithium.
Reason : Energies of orbitals in the same subshell decrease with increase in atomic number.

\(\mathrm{Zn}(s)+\mathrm{Cl}_{2}(1 \mathrm{~atm}) \longrightarrow \mathrm{Zn}^{2+}+2 \mathrm{Cl}^{-} ; E^{\circ}=2.0 \mathrm{~V}\) To increase the emf of the above cell

A neutral water molecule, modeled as an electric dipole with an effective charge equal to one elementary charge (\(e = 1.6 \times 10^{-19} \text{ C}\)), is placed in an electric field \(E = 2.5 \times 10^4 \text{ NC}^{-1}\). The work done to rotate it by \(180^\circ\) from its stable equilibrium position is \(5 \times 10^{-25} \text{ J}\). Find the approximate separation of the centre of charges.

The temperature of two bodies \(A\) and \(B\) are \(727^{\circ} \mathrm{C}\) and \(327^{\circ} \mathrm{C}\) respectively, the ratio \(H_{A}: H_{B}\) of the rates of heat radiated by them is

Two statements, Assertion and Reason are given. With reference to them, choose the correct option.
Assertion: Hydrolysis of 2-Bromo-2-methylpropane follows \(S_N1\) mechanism which involves 2 steps and the first step is:

Reason: The energy required to cleave C – Br is taken from the energy released due to Inductive effect and hyper-conjugative effect.