A metallic sphere of capacitance C1, charged to electric potential V1 is connected by a metal wire to another metallic sphere of capacitance C2 charged to electric potential V2. The amount of heat produced in connecting the wire during the process is:
1.C1C22(C1+C2)(V1+V2)2
2. C1C22(C1+C2)(V1-V2)2
3. C1C2C1+C2(V1-V2)2
4. zero
The electric potential at the surface of a charged solid sphere of insulator is 20V. The value of electric potential at its centre will be
1. 30V
2. 20V
3. 40V
4. Zero
The capacitance of a parallel plate capacitor is C. If a dielectric slab of thickness equal to one-fourth of the plate separation and dielectric constant K is inserted between the plates, then new capacitance become
1. KC2(K+1)
2. 2KCK+1
3. 5KC4K+1
4. 4KC3K+1
The electric potential at a point at distance 'r' from a short dipole is proportional to
1. r2
2. r-1
3. r-2
4. r1
A hollow charged metal spherical shell has radius R. If the potential difference between its surface and a point at a distance 3R from the center is V, then the value of electric field intensity at a point at distance 4R from the center is
1. 3V19R
2. V6R
3. 3V32R
4. 3V16R
Capacitors C1=10μF and C2=30μF are connected in series across a source of emf 20KV. The potential difference across C1 will be
1. 5 KV
2. 15 KV
3. 10 KV
4. 20 KV
The equivalent capacitance between A and B is as the given figure:
1. 16πϵ0r
2. 4πϵ0r
3. 8πϵ0r
4. None of these
Two metallic spheres of radii 2cm and 3cm are given charges 6mC and 4mC respectively. The final charge on the smaller sphere will be if they are connected by a conducting wire
1. 4mC
2.6mC
3. 5mC
4. 10mC
1. | v | 2. | v√2 |
3. | v√2 | 4. | 2v |