- AWork is done on the charge.
- BWork is done by the charge.
- CWork done is constant.
- DNo work is done.
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Focal length of a converging lens in air is R. If it is dipped in water of refractive index 1.33, then its focal length will be around (Refractive index of lens material is 1.5)
|
(a) R |
(b) 2R |
(c) 4R |
(d) R / 2 |
Electric room radiator which operates at 225 volts has resistance of 50 ohms. Power of the radiator is approximately
|
(a) 100 W |
(b) 450 W |
(c) 750 W |
(d) 1000 W |
A hydrogen like atom of atomic number Z is in an excited state of quantum number 2n. It can emit a maximum energy photon of 204 eV. If it makes a transition to quantum state n, a photon of energy 40.8 eV is emitted. The value of n will be
|
(a) 1 |
(b) 2 |
(c) 3 |
(d) 4 |
Laser beams are used to measure long distances because
|
(a) They are monochromatic |
(b) They are highly polarised |
|
(c) They are coherent |
(d) They have high degree of parallelism |
A series combination of three capacitors of capacities 1μF, 2 μF and 8 μF is connected to a battery of e.m.f. 13 volt. The potential difference across the plates of 2 μF capacitor will be
|
(a) 1 V |
(b) 8V |
(c) 4V |
(d) |