- ✓$\vec{\tau}=\vec{p} \times \vec{E}$
- B$\vec{\tau}=\overrightarrow{ E } \times \vec{p}$
- C$\vec{\tau}=\frac{1}{4 \pi \in_0} \vec{p} \times \vec{E}$
- D$\vec{\tau}=\vec{p} \cdot \overrightarrow{ E }$
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The refractive indices of water and glass with respect to air are 1.2 and 1.5 respectively. The refractive index of glass with respect to water is
|
(a) 0.6 |
(b) 0.8 |
(c) 1.25 |
(d) 1.75 |
In hydrogen atom, an electron is revolving in the orbit of radius 0.53 with 6.6
rotations/second. Magnetic field produced at the centre of the orbit is
|
(a) 0.125 |
(b) 1.25 |
(c) 12.5 |
(d) 125 |
Two long straight parallel conductors separated by a distance of 0.5m carry currents of 5A and 8A in the same direction. The force per unit length experienced by each other is
|
(a) 1.3 |
(b) 1.6 |
|
(c) 16 |
(d) 16 |
A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m then
|
(a) Number of electrons emitted is half the initial number |
|
(b) Each emitted electron carries half the initial energy |
|
(c) Number of electrons emitted is a quarter of the initial number |
|
(d) Each emitted electron carries one quarter of the initial energy |
In the experiment of potentiometer, at balance, there is no current in the
|
(a) Main circuit |
|
(b) Galvanometer circuit |
|
(c) Potentiometer circuit |
|
(d) Both main and galvanometer circuits |