Electromagnetic Waves — Physics STD 12 Science — Question

When the number of nucleons in a nucleus increases, the binding energy per nucleon:

A wall clock uses a vertical spring-mass system to measure the time. Each time the mass reaches an extreme position, the clock advances by a second. The clock gives correct time at the equator. If the clock is taken to the poles it will:

1. Run slow.
2. Run fast.
3. Stop working.
4. Give correct time.

A positively charged particle moving in east direction enters a region of uniform magnetic field directed vertically upwards. What will be the path of the particle?

The potential gradient at which the dielectric of a condenser just gets punctured is called

(a) Dielectric constant

(b) Dielectric strength

(c) Dielectric resistance

(d) Dielectric number

If the voltage of X-ray tube is doubled, the intensity of X-rays will become

(a) Half

(b) Unchanged

(c) Double

(d) Four times

During mean life of a radioactive element, the fraction that disintegrates is

(a) e

(b)

(c)

(d)

No. of protons and neutrons in hydrogen atom are respectively __________ .

The capacity of the parallel plate capacitor increases when:

A rectangular loop carrying a current i₁​, is situated near a long straight wire carrying a steady current i₂​. The wire is parallel to one of the sides of the loop and is in the plane of the loop as shown in the figure. Then the current loop will:

X-rays of wavelength 0.1 Å allowed to fall on a metal get scattered. The wavelength of scattered radiation is 0.111 Å. If h = 6.624 × 10^–34 J-s and m₀ = 9 × 10^–31 kg, then the direction of the scattered photons will be

(a) cos–1 (0.547)

(b) cos–1 (0.4484)

(c) cos–1 (0.5)

(d) cos–1 (0.3)