Polar molecules are the molecules:
1. | that acquires a dipole moment only when the magnetic field is absent. |
2. | has a permanent electric dipole moment. |
3. | has zero dipole moment. |
4. | that acquire a dipole moment only in the presence of an electric field due to displacement of charges. |
1. | S2,√3gS2S2,√3gS2 | 2. | S4,√3gS2S4,√3gS2 |
3. | S4,3gS2S4,3gS2 | 4. | S4,√3gS3S4,√3gS3 |
Match Column I and Column II with appropriate relations.
Column I | Column II | ||
(A) | Drift Velocity | (P) | mne2ρmne2ρ |
(B) | Electrical Resistivity | (Q) | nevdnevd |
(C) | Relaxation Period | (R) | eEmτeEmτ |
(D) | Current Density | (S) | EJEJ |
(A) | (B) | (C) | (D) | |
1. | (R) | (P) | (S) | (Q) |
2. | (R) | (Q) | (S) | (P) |
3. | (R) | (S) | (P) | (Q) |
4. | (R) | (S) | (Q) | (P) |
If force [F][F], acceleration [A][A] and time [T][T] are chosen as the fundamental physical quantities, then find the dimensions of energy:
1. [FAT−1][FAT−1]
2. [FA−1T][FA−1T]
3. [FAT][FAT]
4. [FAT2][FAT2]
The escape velocity from the Earth's surface is vv. The escape velocity from the surface of another planet having a radius, four times that of Earth and the same mass density is:
1. | 3v3v | 2. | 4v4v |
3. | vv | 4. | 2v2v |
A small block slides down on a smooth inclined plane starting from rest at time t=0.t=0. Let SnSn be the distance traveled by the block in the interval t=n−1t=n−1 to t=n.t=n. Then the ratio SnSn+1SnSn+1 is:
1. | 2n+12n−12n+12n−1 | 2. | 2n2n−12n2n−1 |
3. | 2n−12n2n−12n | 4. | 2n−12n+12n−12n+1 |
The velocity of a small ball of mass MM and density dd, when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is d2d2 then the viscous force acting on the ball will be:
1. | 3Mg23Mg2 | 2. | 2Mg2Mg |
3. | Mg2Mg2 | 4. | MgMg |
A thick current-carrying cable of radius 'RR' carries current ′I′ uniformly distributed across its cross-section. The variation of magnetic field B(r) due to the cable with the distance 'r' from the axis of the cable is represented by:
1. | |
2. | |
3. | 4. |
Find the value of the angle of emergence from the prism given below for the incidence ray shown. The refractive index of the glass is √3.
1. 45∘
2. 90∘
3. 60∘
4. 30∘
A screw gauge gives the following readings when used to measure the diameter of a wire:
Main scale reading: 0 mm
Circular scale reading: 52 divisions
Given that 1 mm on the main scale corresponds to 100 divisions on the circular scale, the diameter of the wire that can be inferred from the given data is:
1. | 0.26 cm | 2. | 0.052 cm |
3. | 0.52 cm | 4. | 0.026 cm |