S.I unit of magnetic flux is :

• tesla

• oersted

• weber

• gauss

Across each of two capacitors of capacitance 1F, a potential difference of 10 V is applied. Then the positive plate of one is connected to the negative plate of the other, and the negative plate of one is connected to the positive plate of the other. After contact :

• charge on each is zero

• charge on each is same but non zero

• charge on each is different but non zero

Kirchhoff's law of junction, $\mathrm{\Sigma }$I = 0, is based on :

• conservation of energy

• conservation of charge

• conservation of energy as well as charge

• conservation of momentum

Charges 4Q, q and Q are placed along x-axis at positions x = 0, x = l/2 and x = l, respectively. Find the value of q so that the force on charge Q is zero:

• Q

• $\frac{\mathrm{Q}}{2}$

• $-\frac{\mathrm{Q}}{2}$

• -Q

Two small charged spheres A and B have charges 10 C and 40 C respectively and are held at a separation of 90 cm from each other. At what distance from A, the electric intensity would be zero?

• 22.5 cm

• 18 cm

• 36 cm

• 30 cm

In a cyclotron, if a deuteron can gain the energy of 40 MeV, then a proton can gain the energy of:

• 40 MeV

• 80 MeV

• 20 MeV

• 60 MeV

An electron, moving in a uniform magnetic field of induction of intensity B, has its radius directly proportional to:

• its charge

• magnetic field

• speed

• none of these

If the percentage change in current through a resistor is 1%, then the change in power through it would be:

• 1 %

• 2 %

• 1.7 %

• 0.5 %

39.

3 identical bulbs are connected in series and these together dissipate a power P. If now the bulbs are connected in parallel, then the power dissipated will be:

• P/3

• 3P

• 9P

• P/9

A charged particle moves in an electric field from A to B, then from B to A :

• If W_AB > W_BA, then the field is conservative

• If W_AB + W_BA = 0, then the field is conservative

• If W_AB + W_BA > 0, then the field is conservative

• If W_AB = W_BA, then the field is conservative