Welcome to Sarthaks eConnect Question Bank
Practice Online Test Series for JEE Main 2018 & NEET 2018
Consider two satellites A and B revolving around the earth in circular orbits with radii `R_A` and `R_B` .Their periods `T_A` and `T_B` are 8 h and 1 h respectively. The ratio `(R_A /R_B)` is equal to
A mixture consists of two radioactive materials `A_1 and A_2` with half lives of 20s and 10s respectively. Initially the mixture has 40g of `A_1`and 160 g of `A_2` .The amount of the two in the mixture will become equal after
Electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to the first excited state.The ratio of the wavelengths `lambda_1 : lambda_2` emitted in the two cases :
A photosensitive metallic surface has work function, hv0 .If photons of energy `2hv_0` fall on this surface, the electrons come out with a maximum velocity of `4xx10^6` m/s .When the photon energy is increased to `5hv_0` ,then maximukm velocity of photoelectrons will be
In a circuit L, C and R are connected in series with an alternating voltage source of frequency f. The current leads the voltage by `45^o` .The value of C is
A coil of inductive reactance 31 ohm has a resistance of 8 ohm. It is placed in series with a condenser of capacitive reactance 25 ohm. The combination is connected to an ac source of 110V. The power factor of the circuit is
An insulating rod of length L moves uniformly with velocity `v` in a uniform magnetic field of induction B being perpendicular to B and also perpendicular to the length L. The induced emf between the two ends of the rod is :
A wire carrying current ‘i’ is bent as shown in figure and placed in the plane of paper in a uniform magnetic field `vecB` .Force experienced by the wire can be expressed as :
The magnetic field lines due to a bar magnet are correctly shown is :
The resistances 500 `Omega` and 1000 `Omega` are connected in series with a battery of 1.5 volt. The voltage across the 1000 `Omega` resistance is measurede by a voltmeter having a resistance of 1000`Omega` .The reading in the voltmeter would be :
Two conductors, both having same length and same area of cross-section, are joined in parallel as shown in figure.Their resistivities are `rho` and `3rho` .Equivalent resistivity of their combination is :
The figure shows electric lines of force. If `E_A` and `E_B` are electric fields at A and B and distance AB = r, then
If a positively charged pendulum is oscillating in a uniform electric field as shown in figure.Its time period as compared to that when it was uncharged :
Two identical plates of metal are welded end to end as shown in figure.(A); 20 cal of heat flows through it in 4 minute.If the plates are welded as shown in figure (B) , the same amount of heat will flow through the plates in:
Two liquids of equal volume are thoroughly mixed. If their specific heats are `C_2,C_2 `,temperatures `theta_1,theta_2` and densities `d_1,d_2` respectively, the final temperature of the mixture is:
Two particles execute SHM of the same amplitude and frequency along the same straight line. They pass one another when going in opposite directions, each time their displacement is half of their amplitude. What is the phase difference between them?
A horizontal pipe line carries water in a streamline flow. At a point along the pipe where the cross-sectional area is 10 `cm^2` ,the water velocity is 1m/ s and the pressure is 2000 Pa. What is the pressure of water at another point where the cross-sectional area is 5 `cm^2` ?
A bomb of mass 9 kg explodes into two pieces of masses 3kg and 6 kg.The velocity of mass 3kg is 16 m/s.The KE of mass 6kg.in joule is :
A mass is performing vertical circular motion (see figure).If the average velocity of the particle is increased, then at which point the string will break:
Two blocks are connected by a spring as shown in figure.The blocks are placed on a horizontal rough surface with `mu` as the coefficient of friction between the blocks and the surface.
Minimum horizontal force on `M_1` so as to move `M_2` is :
