Two waves of amplitudes 3 m and 2 m, respectively superimpose at a point in the same phase. The resultant amplitude would be

The height of transmitting antenna and receiving antenna are 45 m and 80 m. If the radius of earth is \( 6.4 \times 10^6 \text{ m} \), then the maximum distance between the two antennas for satisfactory communication in LOS mode is:

Helium gas is filled in a transparent balloon which is kept in air. The balloon behaves as:

An LCR series circuit with L = 100 mH, C = 100 \( \mu \)F, R = 10 \( \Omega \) is connected to an AC source of emf 220 V. The resonant frequency of the circuit will be nearly

The critical angle of incidence \( i_c \) for a ray incident from a denser to a rarer medium, is that angle for which

Choose the correct statements, when a cell of emf E and internal resistance r connected to external resistance R having current I flowing through the circuit is:
A. Potential difference across the terminals of the cell in a closed circuit having resistance R is always less than the emf.
B. For practical calculations, the internal resistance of the cells in the circuits may be neglected when the current I is such that E >> I.
C. Terminal potential difference in a closed circuit is always more than emf E.
D. Terminal potential difference versus current graph for a cell with closed circuit having resistance R is a straight line with a negative slope.
Choose the correct answer from the options given below:

Which of the following statements are correct?
A. The various lines in the atomic spectra are produced when electrons jump from higher energy state to a lower energy state.
B. An accelerated atomic electron must spiral into the nucleus as it losses energy.
C. Rutherford scattering determines an upper limit to the size of the nucleus.
D. Angular momentum of the electron orbiting around the nucleus is not quantised.

The person with karyotype 44+XXY is suffering from:

Progestasert and LNG-20 are examples of:

Two persons A and B throw a die alternately till one of them gets a six and wins the game. If A begins, then the probabilities of winning of A and B respectively are

If 'n' identical resistors, each of value 'R' are first connected in series to a battery of emf 'E' and internal resistance 'R', the current drawn is 'I'. Now if they are connected in parallel, then the current drawn is '5 I'. The value of n is

Gause's 'Competitive Exclusion Principle' states that -

The value of \(\int e^x\left[f(x)+f^{\prime}(x)\right] d x\) is :