A/√2
2/√A
2 A
√2 A
Correct answer is B
If I = 2 Sin wt; but in a.c. circuit current I = I0 Sin wt; thus comparing the two equations, it implies that I0 = 2A; Again, the root means square (I(rms)) of an a.c. current is the value of the d.c. current that will dissipate the same amount of heat in a given resistance as the a.c.
and I(rms) = I0/√2 = 2.0A/√2
I and IV only
I and III only
II and IV only
II and III only
Correct answer is B
Electricity conduction through gases is usually done under low pressure (I) and high voltage (III). Thus /B/
The particles emitted when \( ^{39}_{19}K \text{ decay to } ^{39}_{19}K \) is
gamma
beta
electron
alpha
Correct answer is A
3919K 3919K.
Since neither the mass number (39), nor the atomic number (19) is affected by the emission,the particles emitted can only be gamma ray, which is not a charge particle, but simply a radiation.
2.0Ω
1.0Ω
2.5Ω
1.5Ω
Correct answer is A
let the internal resistance of the cell = r,
therefore E = I (R+r)
(i) E = 0.4(4+r), (ii) E = 0.2 (10+r)
therefore 0.4 (4+r)= 0.2 (10+r)
1.6 + 0.4r = 2.0 * 0.2r
0.4r - 0.2r = 2.0 - 1.6
therefore 0.2r = 0.4 => r = 0.4/0.2 = 2Ω
therefore r = 2Ω
e/4πԐoGm
e2/Gm2
Gm2/4πԐoe2
e2/4πԐoeGm2
Correct answer is D
Electrostatic force = FE = e2/4λEod2
Gravitational force = FG = GM2/d2