Physics Test - ...

Copper and iron wires of same length and diameter are in series and connected across a battery. The resistivity of copper is about one-sixth of the iron. If E₁ and E₂ are the electric fields in the copper and iron wires respectively, then which of the following is correct?

On a hypothetical planet satellite can only revolve in quantized energy level i.e. magnitude of energy of a satellite is integer multiple of a fixed energy. If two successive orbit have radius R and$\frac{3R}{2}$what could be maximum radius of satellite

Two bodies A and B have emissivity’s 0.5 and 0.8 respectively. At some temperatures, the two bodies have maximum spectral emissive powers at wavelength 8000 A^o and 4000 A^o respectively. The ratio of their emissive powers at these temperatures is:

In the circuit shown in figure find the current in branch AB of the circuit :

A point object moves on a circular path such that distance covered by it is given by function
$S=\left(\frac{t^2}{2}+2t\right)$Meter (t in second). The ratio of the magnitude of acceleration at t = 2 sec.
And t = 5 sec. is 1: 2 then radius of the circle is

A uniform electric field E is present horizontally along the paper throughout the region and uniform magnetic field B0 is present horizontally (perpendicular to plane of paper in inward direction) right to the line AB. A charge particle having charge q and mass m is projected vertically upward and it crosses the line AB after time t₀. Find the speed of projection if particle moves with constant velocity after t₀. (Given qE = mg)

Consider a L-R circuit shown in figure. There is no current in circuit. Switch S is closed at t = 0, time instant when current in inductor is equal to current in resistor 2R will be :

An unknown particle$\frac{1285}{513}Za$originally at rest emits 5 alpha particles with speed 11385 km/h. Find the recoil speed of the unknown daughter nucleus.