The ratio of minimum wavelengths of Lyman and Balmer series will be
1.25
0.25
5
10
The ratio of the nuclear radii of elements with mass numbers 216 and 125 is
216:125
6 :5
none of these
The spectrum of an oil flame is an example for _____.
line absorption spectrum
band emission spectrum
line emission spectrum
continuous emission spectrum
The temperature of a gas contained in a closed vessel of constant volume increases by 1°C when the pressure of the gas is increased by 1%. The initial temperature of the gas is ______.
100°C
200 K
100 K
273°C
The wavelength of the light used in Young's double slit experiment is l. The intensity at a point on the screen where the path difference is is I. If I0 denotes the maximum intensity, then the ratio of I and I0 is ______.
0.707
0.75
0.866
0.5
There is a uniform magnetic field directed perpendicular and into the plane of the paper. An irregular shaped conducting loop is slowly changing into a circular loop in the plane of the paper. Then ______.
AC is induced in the loop.
no current is induced in the loop.
current is induced in the loop in the anti-clockwise direction.
current is induced in the loop in the clockwise direction.
Three liquids of equal masses are taken in three identical cubical vessels A, B and C. Their densities are PA, PB and PC respectively. But PA < PB < PC. The force exerted by the liquid on the base of the cubical vessel is ______
the same in all the vessels
maximum in vessel A
maximum in vessel C
minimum in vessel C
Two identical conducting balls A and B have positive charges q1 and q2 respectively. But q1 ≠ q2. The balls are brought together so that they touch each other and then kept in their original positions. The force between them is ______.
same as that before the balls touched
zero
less than that before the balls touched
greater than that before the balls touched
Two identical metal spheres charged with +12mF and -8mF are kept at certain distance in air. They are brought into contact and then kept at the same distance. The ratio of the magnitudes of electrostatic forces between them before and after contact is