Sample question paper

A point charge +Q is placed at the centre of a spherical Gaussian surface of radius R. If the radius of the sphere is doubled, the electric flux through the surface will

1. Abecome half
2. Bbecome double
3. Cremain the same
4. Dbecome four times

If two identical heaters each rated as (1000 W, 220 V) are connected in parallel to 220 V, then the total power consumed is-

1. A200 W
2. B250 W
3. C2000 W
4. D2500 W

An infinitely long cylinder is kept parallel to a uniform magnetic field B directed along negative y –axis. What will be the direction of induced current as seen from the y axis?

1. Aclockwise of the negative y-axis
2. Banticlockwise of the negative y-axis
3. Cno current will be induced
4. Dalong the direction of the magnetic field

Which one of the following phenomenon is not explained by Huygens’ construction of wave front?

1. ADiffraction
2. BRefraction
3. CReflection
4. DOrigin of spectra

If wave front from star in nearby galaxy is detected by a telescope at the top of some mountain in India then the shape of the wavefront detected will be

1. Adiverging spherical
2. Bconverging spherical
3. Cplane
4. Dcylindrical

The binding energy per nucleon curve shows a maximum around mass number A=56. What does this imply about nuclei near iron (Fe)?

1. AThey are the least stable nuclei.
2. BThey are the most tightly bound nuclei.
3. CThey undergo spontaneous fission releasing maximum energy.
4. DThey cannot participate in nuclear reactions.

If nucleus scaled to football size is approximately 22cm, then the radius of the orbit of electron will be approximately:

1. A22 cm
2. B22 m
3. C22 km
4. D22000 km